/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

%{
package sqlparser

func setParseTree(yylex interface{}, stmt Statement) {
  yylex.(*Tokenizer).ParseTree = stmt
}

func setAllowComments(yylex interface{}, allow bool) {
  yylex.(*Tokenizer).AllowComments = allow
}

func setDDL(yylex interface{}, ddl *DDL) {
  yylex.(*Tokenizer).partialDDL = ddl
}

func incNesting(yylex interface{}) bool {
  yylex.(*Tokenizer).nesting++
  if yylex.(*Tokenizer).nesting == 200 {
    return true
  }
  return false
}

func decNesting(yylex interface{}) {
  yylex.(*Tokenizer).nesting--
}

func forceEOF(yylex interface{}) {
  yylex.(*Tokenizer).ForceEOF = true
}

%}

%union {
  empty         struct{}
  statement     Statement
  selStmt       SelectStatement
  ddl           *DDL
  ins           *Insert
  byt           byte
  bytes         []byte
  bytes2        [][]byte
  str           string
  strs          []string
  selectExprs   SelectExprs
  selectExpr    SelectExpr
  columns       Columns
  colName       *ColName
  tableExprs    TableExprs
  tableExpr     TableExpr
  tableName     TableName
  indexHints    *IndexHints
  expr          Expr
  exprs         Exprs
  boolVal       BoolVal
  colTuple      ColTuple
  values        Values
  valTuple      ValTuple
  subquery      *Subquery
  whens         []*When
  when          *When
  orderBy       OrderBy
  order         *Order
  limit         *Limit
  updateExprs   UpdateExprs
  updateExpr    *UpdateExpr
  colIdent      ColIdent
  colIdents     []ColIdent
  tableIdent    TableIdent
  convertType   *ConvertType
  aliasedTableName *AliasedTableExpr
  TableSpec  *TableSpec
  TableOptions TableOptions
  columnType    ColumnType
  colKeyOpt     ColumnKeyOption
  optVal        *SQLVal
  LengthScaleOption LengthScaleOption
  columnDefinition *ColumnDefinition
  indexDefinition *IndexDefinition
  indexInfo     *IndexInfo
  indexColumn   *IndexColumn
  indexColumns  []*IndexColumn
}

%token LEX_ERROR
%left <bytes> UNION
%token <bytes> SELECT INSERT UPDATE DELETE FROM WHERE GROUP HAVING ORDER BY LIMIT OFFSET FOR
%token <bytes> ALL DISTINCT AS EXISTS ASC DESC INTO DUPLICATE KEY DEFAULT SET LOCK
%token <bytes> VALUES LAST_INSERT_ID
%token <bytes> NEXT VALUE SHARE MODE
%token <bytes> SQL_NO_CACHE SQL_CACHE
%left <bytes> JOIN STRAIGHT_JOIN LEFT RIGHT INNER OUTER CROSS NATURAL USE FORCE
%left <bytes> ON
%token <empty> '(' ',' ')'
%token <bytes> ID HEX STRING INTEGRAL FLOAT HEXNUM VALUE_ARG LIST_ARG COMMENT COMMENT_KEYWORD
%token <bytes> NULL TRUE FALSE

// Precedence dictated by mysql. But the vitess grammar is simplified.
// Some of these operators don't conflict in our situation. Nevertheless,
// it's better to have these listed in the correct order. Also, we don't
// support all operators yet.
%left <bytes> OR
%left <bytes> AND
%right <bytes> NOT '!'
%left <bytes> BETWEEN CASE WHEN THEN ELSE END
%left <bytes> '=' '<' '>' LE GE NE NULL_SAFE_EQUAL IS LIKE REGEXP IN
%left <bytes> '|'
%left <bytes> '&'
%left <bytes> SHIFT_LEFT SHIFT_RIGHT
%left <bytes> '+' '-'
%left <bytes> '*' '/' DIV '%' MOD
%left <bytes> '^'
%right <bytes> '~' UNARY
%left <bytes> COLLATE
%right <bytes> BINARY
%right <bytes> INTERVAL
%nonassoc <bytes> '.'

// There is no need to define precedence for the JSON
// operators because the syntax is restricted enough that
// they don't cause conflicts.
%token <empty> JSON_EXTRACT_OP JSON_UNQUOTE_EXTRACT_OP

// DDL Tokens
%token <bytes> CREATE ALTER DROP RENAME ANALYZE ADD MODIFY
%token <bytes> TABLE INDEX VIEW TO IGNORE IF UNIQUE USING PRIMARY COLUMN
%token <bytes> SHOW DESCRIBE EXPLAIN DATE ESCAPE REPAIR OPTIMIZE TRUNCATE

// Type Tokens
%token <bytes> BIT TINYINT SMALLINT MEDIUMINT INT INTEGER BIGINT INTNUM
%token <bytes> REAL DOUBLE FLOAT_TYPE DECIMAL NUMERIC
%token <bytes> TIME TIMESTAMP DATETIME YEAR
%token <bytes> CHAR VARCHAR BOOL CHARACTER VARBINARY NCHAR CHARSET
%token <bytes> TEXT TINYTEXT MEDIUMTEXT LONGTEXT
%token <bytes> BLOB TINYBLOB MEDIUMBLOB LONGBLOB JSON ENUM

// Type Modifiers
%token <bytes> NULLX AUTO_INCREMENT APPROXNUM SIGNED UNSIGNED ZEROFILL

// Supported SHOW tokens
%token <bytes> DATABASES TABLES VITESS_KEYSPACES VITESS_SHARDS VSCHEMA_TABLES WARNINGS VARIABLES EVENTS BINLOG GTID

// Functions
%token <bytes> CURRENT_TIMESTAMP DATABASE CURRENT_DATE
%token <bytes> CURRENT_TIME LOCALTIME LOCALTIMESTAMP
%token <bytes> UTC_DATE UTC_TIME UTC_TIMESTAMP
%token <bytes> REPLACE
%token <bytes> CONVERT CAST
%token <bytes> GROUP_CONCAT SEPARATOR

// Match
%token <bytes> MATCH AGAINST BOOLEAN LANGUAGE WITH QUERY EXPANSION

// MySQL reserved words that are unused by this grammar will map to this token.
%token <bytes> UNUSED

// RadonDB
%token <empty> PARTITION PARTITIONS HASH XA
%type <statement> truncate_statement xa_statement explain_statement kill_statement transaction_statement
%token <bytes> ENGINES STATUS VERSIONS PROCESSLIST QUERYZ TXNZ KILL START TRANSACTION COMMIT SESSION ENGINE

%type <statement> command
%type <selStmt> select_statement base_select union_lhs union_rhs
%type <statement> insert_statement update_statement delete_statement set_statement
%type <statement> create_statement alter_statement drop_statement
%type <ddl> create_table_prefix
%type <statement> analyze_statement show_statement use_statement other_statement
%type <bytes2> comment_opt comment_list
%type <str> union_op insert_or_replace
%type <str> distinct_opt straight_join_opt cache_opt match_option separator_opt binlog_from_opt
%type <expr> like_escape_opt
%type <selectExprs> select_expression_list select_expression_list_opt
%type <selectExpr> select_expression
%type <expr> expression
%type <tableExprs> from_opt table_references
%type <tableExpr> table_reference table_factor join_table
%type <str> inner_join outer_join natural_join
%type <tableName> table_name into_table_name
%type <aliasedTableName> aliased_table_name
%type <indexHints> index_hint_list
%type <colIdents> index_list
%type <expr> where_expression_opt
%type <expr> condition
%type <boolVal> boolean_value
%type <str> compare
%type <ins> insert_data
%type <expr> value value_expression num_val
%type <expr> function_call_keyword function_call_nonkeyword function_call_generic function_call_conflict
%type <str> is_suffix
%type <colTuple> col_tuple
%type <exprs> expression_list
%type <values> tuple_list
%type <valTuple> row_tuple tuple_or_empty
%type <expr> tuple_expression
%type <subquery> subquery
%type <colName> column_name
%type <whens> when_expression_list
%type <when> when_expression
%type <expr> expression_opt else_expression_opt
%type <exprs> group_by_opt
%type <expr> having_opt
%type <orderBy> order_by_opt order_list
%type <order> order
%type <str> asc_desc_opt
%type <limit> limit_opt
%type <str> lock_opt
%type <columns> ins_column_list
%type <updateExprs> on_dup_opt
%type <updateExprs> update_list
%type <updateExpr> update_expression
%type <bytes> for_from
%type <str> ignore_opt default_opt
%type <byt> exists_opt not_exists_opt
%type <empty> non_rename_operation to_opt index_opt
%type <bytes> reserved_keyword non_reserved_keyword
%type <colIdent> sql_id reserved_sql_id col_alias as_ci_opt
%type <tableIdent> table_id reserved_table_id table_alias as_opt_id
%type <empty> as_opt
%type <empty> force_eof ddl_force_eof
%type <str> charset
%type <convertType> convert_type
%type <str> show_statement_type
%type <columnType> column_type
%type <columnType> int_type decimal_type numeric_type time_type char_type
%type <optVal> length_opt column_default_opt column_comment_opt
%type <str> charset_opt collate_opt charset_option engine_option autoincrement_option
%type <boolVal> unsigned_opt zero_fill_opt
%type <LengthScaleOption> float_length_opt decimal_length_opt
%type <boolVal> null_opt auto_increment_opt
%type <colKeyOpt> column_key_opt
%type <strs> enum_values
%type <columnDefinition> column_definition
%type <indexDefinition> index_definition
%type <str> index_or_key
%type <TableSpec> table_spec table_column_list
%type <TableOptions> table_option_list
%type <indexInfo> index_info
%type <indexColumn> index_column
%type <indexColumns> index_column_list

%start any_command

%%

any_command:
  command semicolon_opt
  {
    setParseTree(yylex, $1)
  }

semicolon_opt:
/*empty*/ {}
| ';' {}

command:
  select_statement
  {
    $$ = $1
  }
| insert_statement
| update_statement
| delete_statement
| set_statement
| create_statement
| alter_statement
| drop_statement
| truncate_statement
| analyze_statement
| show_statement
| use_statement
| xa_statement
| explain_statement
| kill_statement
| transaction_statement
| other_statement

select_statement:
  base_select order_by_opt limit_opt lock_opt
  {
    sel := $1.(*Select)
    sel.OrderBy = $2
    sel.Limit = $3
    sel.Lock = $4
    $$ = sel
  }
| union_lhs union_op union_rhs order_by_opt limit_opt lock_opt
  {
    $$ = &Union{Type: $2, Left: $1, Right: $3, OrderBy: $4, Limit: $5, Lock: $6}
  }
| SELECT comment_opt cache_opt NEXT num_val for_from table_name
  {
    $$ = &Select{Comments: Comments($2), Cache: $3, SelectExprs: SelectExprs{Nextval{Expr: $5}}, From: TableExprs{&AliasedTableExpr{Expr: $7}}}
  }

// base_select is an unparenthesized SELECT with no order by clause or beyond.
base_select:
  SELECT comment_opt cache_opt distinct_opt straight_join_opt select_expression_list from_opt where_expression_opt group_by_opt having_opt
  {
    $$ = &Select{Comments: Comments($2), Cache: $3, Distinct: $4, Hints: $5, SelectExprs: $6, From: $7, Where: NewWhere(WhereStr, $8), GroupBy: GroupBy($9), Having: NewWhere(HavingStr, $10)}
  }

union_lhs:
  select_statement
  {
    $$ = $1
  }
| openb select_statement closeb
  {
    $$ = &ParenSelect{Select: $2}
  }

union_rhs:
  base_select
  {
    $$ = $1
  }
| openb select_statement closeb
  {
    $$ = &ParenSelect{Select: $2}
  }


insert_statement:
  insert_or_replace comment_opt ignore_opt into_table_name insert_data on_dup_opt
  {
    // insert_data returns a *Insert pre-filled with Columns & Values
    ins := $5
    ins.Action = $1
    ins.Comments = $2
    ins.Ignore = $3
    ins.Table = $4
    ins.OnDup = OnDup($6)
    $$ = ins
  }
| insert_or_replace comment_opt ignore_opt into_table_name SET update_list on_dup_opt
  {
    cols := make(Columns, 0, len($6))
    vals := make(ValTuple, 0, len($7))
    for _, updateList := range $6 {
      cols = append(cols, updateList.Name.Name)
      vals = append(vals, updateList.Expr)
    }
    $$ = &Insert{Action: $1, Comments: Comments($2), Ignore: $3, Table: $4, Columns: cols, Rows: Values{vals}, OnDup: OnDup($7)}
  }

insert_or_replace:
  INSERT
  {
    $$ = InsertStr
  }
| REPLACE
  {
    $$ = ReplaceStr
  }

update_statement:
  UPDATE comment_opt table_name SET update_list where_expression_opt order_by_opt limit_opt
  {
    $$ = &Update{Comments: Comments($2), Table: $3, Exprs: $5, Where: NewWhere(WhereStr, $6), OrderBy: $7, Limit: $8}
  }

delete_statement:
  DELETE comment_opt FROM table_name where_expression_opt order_by_opt limit_opt
  {
    $$ = &Delete{Comments: Comments($2), Table: $4, Where: NewWhere(WhereStr, $5), OrderBy: $6, Limit: $7}
  }

set_statement:
  SET force_eof
  {
    $$ = &Set{}
  }

create_statement:
  create_table_prefix table_spec
  {
    $1.Action = CreateTableStr
    $1.TableSpec = $2
    $$ = $1
  }
| create_table_prefix table_spec PARTITION BY HASH openb ID closeb ddl_force_eof
  {
    $1.Action = CreateTableStr
    $1.TableSpec = $2
    $1.PartitionName = string($7)
    $$ = $1
  }
| CREATE DATABASE not_exists_opt table_id
  {
    var ifnotexists bool
    if $3 != 0 {
      ifnotexists= true
    }
    $$ = &DDL{Action: CreateDBStr, IfNotExists:ifnotexists, Database: $4}
  }
| CREATE INDEX ID ON table_name ddl_force_eof
  {
    // Change this to an alter statement
    $$ = &DDL{Action: CreateIndexStr, IndexName:string($3), Table: $5, NewName:$5}
  }

create_table_prefix:
  CREATE TABLE not_exists_opt table_name
  {
    var ifnotexists bool
    if $3 != 0 {
      ifnotexists= true
    }
    $$ = &DDL{Action: CreateTableStr, IfNotExists:ifnotexists, Table: $4, NewName: $4}
    setDDL(yylex, $$)
  }

table_spec:
  '(' table_column_list ')' table_option_list
  {
    $$ = $2
    $$.Options = $4
  }

table_option_list:
 engine_option autoincrement_option charset_option
  {
    $$.Engine = $1
    $$.Charset = $3
  }

engine_option:
 {
   $$=""
 }
| ENGINE '=' ID
 {
   $$ = string($3)
 }

charset_option:
 {
    $$=""
 }
| DEFAULT CHARSET '=' ID
 {
   $$ = string($4)
 }

autoincrement_option:
 {
    $$=""
 }
| AUTO_INCREMENT '=' INTEGRAL
 {
 }


table_column_list:
  column_definition
  {
    $$ = &TableSpec{}
    $$.AddColumn($1)
  }
| table_column_list ',' column_definition
  {
    $$.AddColumn($3)
  }
| table_column_list ',' index_definition
  {
    $$.AddIndex($3)
  }

column_definition:
  ID column_type null_opt column_default_opt auto_increment_opt column_key_opt column_comment_opt
  {
    $2.NotNull = $3
    $2.Default = $4
    $2.Autoincrement = $5
    $2.KeyOpt = $6
    $2.Comment = $7
    $$ = &ColumnDefinition{Name: NewColIdent(string($1)), Type: $2}
  }
column_type:
  numeric_type unsigned_opt zero_fill_opt
  {
    $$ = $1
    $$.Unsigned = $2
    $$.Zerofill = $3
  }
| char_type
| time_type

numeric_type:
  int_type length_opt
  {
    $$ = $1
    $$.Length = $2
  }
| decimal_type
  {
    $$ = $1
  }

int_type:
  BIT
  {
    $$ = ColumnType{Type: string($1)}
  }
| TINYINT
  {
    $$ = ColumnType{Type: string($1)}
  }
| SMALLINT
  {
    $$ = ColumnType{Type: string($1)}
  }
| MEDIUMINT
  {
    $$ = ColumnType{Type: string($1)}
  }
| INT
  {
    $$ = ColumnType{Type: string($1)}
  }
| INTEGER
  {
    $$ = ColumnType{Type: string($1)}
  }
| BIGINT
  {
    $$ = ColumnType{Type: string($1)}
  }

decimal_type:
REAL float_length_opt
  {
    $$ = ColumnType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }
| DOUBLE float_length_opt
  {
    $$ = ColumnType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }
| FLOAT_TYPE float_length_opt
  {
    $$ = ColumnType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }
| DECIMAL decimal_length_opt
  {
    $$ = ColumnType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }
| NUMERIC decimal_length_opt
  {
    $$ = ColumnType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }

time_type:
  DATE
  {
    $$ = ColumnType{Type: string($1)}
  }
| TIME length_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2}
  }
| TIMESTAMP length_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2}
  }
| DATETIME length_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2}
  }
| YEAR
  {
    $$ = ColumnType{Type: string($1)}
  }

char_type:
  CHAR length_opt charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2, Charset: $3, Collate: $4}
  }
| VARCHAR length_opt charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2, Charset: $3, Collate: $4}
  }
| BINARY length_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2}
  }
| VARBINARY length_opt
  {
    $$ = ColumnType{Type: string($1), Length: $2}
  }
| TEXT charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Charset: $2, Collate: $3}
  }
| TINYTEXT charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Charset: $2, Collate: $3}
  }
| MEDIUMTEXT charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Charset: $2, Collate: $3}
  }
| LONGTEXT charset_opt collate_opt
  {
    $$ = ColumnType{Type: string($1), Charset: $2, Collate: $3}
  }
| BLOB
  {
    $$ = ColumnType{Type: string($1)}
  }
| TINYBLOB
  {
    $$ = ColumnType{Type: string($1)}
  }
| MEDIUMBLOB
  {
    $$ = ColumnType{Type: string($1)}
  }
| LONGBLOB
  {
    $$ = ColumnType{Type: string($1)}
  }
| JSON
  {
    $$ = ColumnType{Type: string($1)}
  }
| ENUM '(' enum_values ')'
  {
    $$ = ColumnType{Type: string($1), EnumValues: $3}
  }

enum_values:
  STRING
  {
    $$ = make([]string, 0, 4)
    $$ = append($$, "'" + string($1) + "'")
  }
| enum_values ',' STRING
  {
    $$ = append($1, "'" + string($3) + "'")
  }

length_opt:
  {
    $$ = nil
  }
| '(' INTEGRAL ')'
  {
    $$ = NewIntVal($2)
  }

float_length_opt:
  {
    $$ = LengthScaleOption{}
  }
| '(' INTEGRAL ',' INTEGRAL ')'
  {
    $$ = LengthScaleOption{
        Length: NewIntVal($2),
        Scale: NewIntVal($4),
    }
  }

decimal_length_opt:
  {
    $$ = LengthScaleOption{}
  }
| '(' INTEGRAL ')'
  {
    $$ = LengthScaleOption{
        Length: NewIntVal($2),
    }
  }
| '(' INTEGRAL ',' INTEGRAL ')'
  {
    $$ = LengthScaleOption{
        Length: NewIntVal($2),
        Scale: NewIntVal($4),
    }
  }

unsigned_opt:
  {
    $$ = BoolVal(false)
  }
| UNSIGNED
  {
    $$ = BoolVal(true)
  }

zero_fill_opt:
  {
    $$ = BoolVal(false)
  }
| ZEROFILL
  {
    $$ = BoolVal(true)
  }

// Null opt returns false to mean NULL (i.e. the default) and true for NOT NULL
null_opt:
  {
    $$ = BoolVal(false)
  }
| NULL
  {
    $$ = BoolVal(false)
  }
| NOT NULL
  {
    $$ = BoolVal(true)
  }

column_default_opt:
  {
    $$ = nil
  }
| DEFAULT STRING
  {
    $$ = NewStrVal($2)
  }
| DEFAULT INTEGRAL
  {
    $$ = NewIntVal($2)
  }
| DEFAULT FLOAT
  {
    $$ = NewFloatVal($2)
  }
| DEFAULT NULL
  {
    $$ = NewValArg($2)
  }

auto_increment_opt:
  {
    $$ = BoolVal(false)
  }
| AUTO_INCREMENT
  {
    $$ = BoolVal(true)
  }

charset_opt:
  {
    $$ = ""
  }
| CHARACTER SET ID
  {
    $$ = string($3)
  }
| CHARACTER SET BINARY
  {
    $$ = string($3)
  }

collate_opt:
  {
    $$ = ""
  }
| COLLATE ID
  {
    $$ = string($2)
  }

column_key_opt:
  {
    $$ = ColKeyNone
  }
| PRIMARY KEY
  {
    $$ = ColKeyPrimary
  }
| KEY
  {
    $$ = ColKey
  }
| UNIQUE KEY
  {
    $$ = ColKeyUniqueKey
  }
| UNIQUE
  {
    $$ = ColKeyUnique
  }

column_comment_opt:
  {
    $$ = nil
  }
| COMMENT_KEYWORD STRING
  {
    $$ = NewStrVal($2)
  }

index_definition:
  index_info '(' index_column_list ')'
  {
    $$ = &IndexDefinition{Info: $1, Columns: $3}
  }

index_info:
  PRIMARY KEY
  {
    $$ = &IndexInfo{Type: string($1) + " " + string($2), Name: NewColIdent("PRIMARY"), Primary: true, Unique: true}
  }
| UNIQUE index_or_key ID
  {
    $$ = &IndexInfo{Type: string($1) + " " + string($2), Name: NewColIdent(string($3)), Unique: true}
  }
| UNIQUE ID
  {
    $$ = &IndexInfo{Type: string($1), Name: NewColIdent(string($2)), Unique: true}
  }
| index_or_key ID
  {
    $$ = &IndexInfo{Type: string($1), Name: NewColIdent(string($2)), Unique: false}
  }

index_or_key:
    INDEX
  {
    $$ = string($1)
  }
  | KEY
  {
    $$ = string($1)
  }

index_column_list:
  index_column
  {
    $$ = []*IndexColumn{$1}
  }
| index_column_list ',' index_column
  {
    $$ = append($$, $3)
  }

index_column:
  sql_id length_opt
  {
      $$ = &IndexColumn{Column: $1, Length: $2}
  }

alter_statement:
  ALTER ignore_opt TABLE table_name non_rename_operation force_eof
  {
    $$ = &DDL{Action: AlterStr, Table: $4, NewName: $4}
  }
| ALTER ignore_opt TABLE table_name RENAME to_opt table_name
  {
    // Change this to a rename statement
    $$ = &DDL{Action: RenameStr, Table: $4, NewName: $7}
  }
| ALTER ignore_opt TABLE table_name RENAME index_opt force_eof
  {
    // Rename an index can just be an alter
    $$ = &DDL{Action: AlterStr, Table: $4, NewName: $4}
  }
| ALTER ignore_opt TABLE table_name ENGINE '=' ID
  {
    $$ = &DDL{Action: AlterEngineStr, Table: $4, NewName:$4, Engine: string($7)}
  }
| ALTER ignore_opt TABLE table_name CONVERT TO CHARACTER SET ID
  {
    $$ = &DDL{Action: AlterCharsetStr, Table: $4, NewName:$4, Charset: string($9)}
  }
| ALTER ignore_opt TABLE table_name ADD COLUMN table_spec
  {
    $$ = &DDL{Action: AlterAddColumnStr, Table: $4, NewName:$4, TableSpec:$7}
  }
| ALTER ignore_opt TABLE table_name DROP COLUMN ID
  {
    $$ = &DDL{Action: AlterDropColumnStr, Table: $4, NewName:$4, DropColumnName:string($7)}
  }
| ALTER ignore_opt TABLE table_name MODIFY COLUMN column_definition
  {
    $$ = &DDL{Action: AlterModifyColumnStr, Table: $4, NewName:$4, ModifyColumnDef:$7}
  }


drop_statement:
  DROP TABLE exists_opt table_name
  {
    var exists bool
    if $3 != 0 {
      exists = true
    }
    $$ = &DDL{Action: DropTableStr, Table: $4, IfExists: exists}
  }
| DROP INDEX ID ON table_name
  {
    // Change this to an alter statement
    $$ = &DDL{Action: DropIndexStr, IndexName:string($3), Table: $5, NewName: $5}
  }
| DROP DATABASE exists_opt table_id
  {
    var exists bool
    if $3 != 0 {
      exists = true
    }
    $$ = &DDL{Action: DropDBStr, Database: $4, IfExists: exists}
  }

truncate_statement:
  TRUNCATE TABLE table_name
  {
    $$ = &DDL{Action: TruncateTableStr, Table: $3, NewName: $3}
  }

analyze_statement:
  ANALYZE TABLE table_name
  {
    $$ = &DDL{Action: AlterStr, Table: $3, NewName: $3}
  }

xa_statement:
  XA force_eof
  {
    $$ = &Xa{}
  }

explain_statement:
  EXPLAIN force_eof
  {
    $$ = &Explain{}
  }

kill_statement:
  KILL INTEGRAL force_eof
  {
    $$ = &Kill{ QueryID: &NumVal{raw: string($2)}}
  }

transaction_statement:
  START TRANSACTION force_eof
  {
    $$ = &Transaction{ Action: StartTxnStr}
  }
| COMMIT force_eof
  {
    $$ = &Transaction{ Action: CommitTxnStr}
  }

show_statement_type:
  ID
  {
    $$ = ShowUnsupportedStr
  }
| reserved_keyword
  {
    switch v := string($1); v {
    case ShowDatabasesStr, ShowTablesStr, ShowEnginesStr, ShowVersionsStr, ShowProcesslistStr, ShowQueryzStr, ShowTxnzStr, ShowStatusStr:
      $$ = v
    default:
      $$ = ShowUnsupportedStr
    }
  }
| non_reserved_keyword
{
    $$ = ShowUnsupportedStr
}

show_statement:
  SHOW show_statement_type force_eof
  {
    $$ = &Show{Type: $2}
  }
| SHOW TABLES FROM table_name force_eof
  {
    $$ = &Show{Type: ShowTablesStr, Database: $4}
  }
| SHOW CREATE TABLE table_name force_eof
  {
    $$ = &Show{Type: ShowCreateTableStr, Table: $4}
  }
| SHOW CREATE DATABASE table_name force_eof
  {
    $$ = &Show{Type: ShowCreateDatabaseStr, Database: $4}
  }
| SHOW WARNINGS force_eof
  {
    $$ = &Show{Type: ShowWarningsStr}
  }
| SHOW VARIABLES force_eof
  {
    $$ = &Show{Type: ShowVariablesStr}
  }
| SHOW BINLOG EVENTS binlog_from_opt limit_opt force_eof
  {
    $$ = &Show{Type: ShowBinlogEventsStr, From: $4, Limit: $5 }
  }

binlog_from_opt:
  {
    $$ = ""
  }
| FROM GTID STRING
  {
    $$ = string($3)
  }

use_statement:
  USE table_id
  {
    $$ = &Use{DBName: $2}
  }

other_statement:
  DESC force_eof
  {
    $$ = &OtherRead{}
  }
| DESCRIBE force_eof
  {
    $$ = &OtherRead{}
  }
| REPAIR force_eof
  {
    $$ = &OtherAdmin{}
  }
| OPTIMIZE force_eof
  {
    $$ = &OtherAdmin{}
  }

comment_opt:
  {
    setAllowComments(yylex, true)
  }
  comment_list
  {
    $$ = $2
    setAllowComments(yylex, false)
  }

comment_list:
  {
    $$ = nil
  }
| comment_list COMMENT
  {
    $$ = append($1, $2)
  }

union_op:
  UNION
  {
    $$ = UnionStr
  }
| UNION ALL
  {
    $$ = UnionAllStr
  }
| UNION DISTINCT
  {
    $$ = UnionDistinctStr
  }

cache_opt:
{
  $$ = ""
}
| SQL_NO_CACHE
{
  $$ = SQLNoCacheStr
}
| SQL_CACHE
{
  $$ = SQLCacheStr
}

distinct_opt:
  {
    $$ = ""
  }
| DISTINCT
  {
    $$ = DistinctStr
  }

straight_join_opt:
  {
    $$ = ""
  }
| STRAIGHT_JOIN
  {
    $$ = StraightJoinHint
  }

select_expression_list_opt:
  {
    $$ = nil
  }
| select_expression_list
  {
    $$ = $1
  }

select_expression_list:
  select_expression
  {
    $$ = SelectExprs{$1}
  }
| select_expression_list ',' select_expression
  {
    $$ = append($$, $3)
  }

select_expression:
  '*'
  {
    $$ = &StarExpr{}
  }
| expression as_ci_opt
  {
    $$ = &AliasedExpr{Expr: $1, As: $2}
  }
| table_id '.' '*'
  {
    $$ = &StarExpr{TableName: TableName{Name: $1}}
  }
| table_id '.' reserved_table_id '.' '*'
  {
    $$ = &StarExpr{TableName: TableName{Qualifier: $1, Name: $3}}
  }

as_ci_opt:
  {
    $$ = ColIdent{}
  }
| col_alias
  {
    $$ = $1
  }
| AS col_alias
  {
    $$ = $2
  }

col_alias:
  sql_id
| STRING
  {
    $$ = NewColIdent(string($1))
  }

from_opt:
  {
    $$ = TableExprs{&AliasedTableExpr{Expr:TableName{Name: NewTableIdent("dual")}}}
  }
| FROM table_references
  {
    $$ = $2
  }

table_references:
  table_reference
  {
    $$ = TableExprs{$1}
  }
| table_references ',' table_reference
  {
    $$ = append($$, $3)
  }

table_reference:
  table_factor
| join_table

table_factor:
  aliased_table_name
  {
    $$ = $1
  }
| subquery as_opt table_id
  {
    $$ = &AliasedTableExpr{Expr:$1, As: $3}
  }
| openb table_references closeb
  {
    $$ = &ParenTableExpr{Exprs: $2}
  }

aliased_table_name:
table_name as_opt_id index_hint_list
  {
    $$ = &AliasedTableExpr{Expr:$1, As: $2, Hints: $3}
  }

// There is a grammar conflict here:
// 1: INSERT INTO a SELECT * FROM b JOIN c ON b.i = c.i
// 2: INSERT INTO a SELECT * FROM b JOIN c ON DUPLICATE KEY UPDATE a.i = 1
// When yacc encounters the ON clause, it cannot determine which way to
// resolve. The %prec override below makes the parser choose the
// first construct, which automatically makes the second construct a
// syntax error. This is the same behavior as MySQL.
join_table:
  table_reference inner_join table_factor %prec JOIN
  {
    $$ = &JoinTableExpr{LeftExpr: $1, Join: $2, RightExpr: $3}
  }
| table_reference inner_join table_factor ON expression
  {
    $$ = &JoinTableExpr{LeftExpr: $1, Join: $2, RightExpr: $3, On: $5}
  }
| table_reference outer_join table_reference ON expression
  {
    $$ = &JoinTableExpr{LeftExpr: $1, Join: $2, RightExpr: $3, On: $5}
  }
| table_reference natural_join table_factor
  {
    $$ = &JoinTableExpr{LeftExpr: $1, Join: $2, RightExpr: $3}
  }

as_opt:
  { $$ = struct{}{} }
| AS
  { $$ = struct{}{} }

as_opt_id:
  {
    $$ = NewTableIdent("")
  }
| table_alias
  {
    $$ = $1
  }
| AS table_alias
  {
    $$ = $2
  }

table_alias:
  table_id
| STRING
  {
    $$ = NewTableIdent(string($1))
  }

inner_join:
  JOIN
  {
    $$ = JoinStr
  }
| INNER JOIN
  {
    $$ = JoinStr
  }
| CROSS JOIN
  {
    $$ = JoinStr
  }
| STRAIGHT_JOIN
  {
    $$ = StraightJoinStr
  }

outer_join:
  LEFT JOIN
  {
    $$ = LeftJoinStr
  }
| LEFT OUTER JOIN
  {
    $$ = LeftJoinStr
  }
| RIGHT JOIN
  {
    $$ = RightJoinStr
  }
| RIGHT OUTER JOIN
  {
    $$ = RightJoinStr
  }

natural_join:
 NATURAL JOIN
  {
    $$ = NaturalJoinStr
  }
| NATURAL outer_join
  {
    if $2 == LeftJoinStr {
      $$ = NaturalLeftJoinStr
    } else {
      $$ = NaturalRightJoinStr
    }
  }

into_table_name:
  INTO table_name
  {
    $$ = $2
  }
| table_name
  {
    $$ = $1
  }

table_name:
  table_id
  {
    $$ = TableName{Name: $1}
  }
| table_id '.' reserved_table_id
  {
    $$ = TableName{Qualifier: $1, Name: $3}
  }

index_hint_list:
  {
    $$ = nil
  }
| USE INDEX openb index_list closeb
  {
    $$ = &IndexHints{Type: UseStr, Indexes: $4}
  }
| IGNORE INDEX openb index_list closeb
  {
    $$ = &IndexHints{Type: IgnoreStr, Indexes: $4}
  }
| FORCE INDEX openb index_list closeb
  {
    $$ = &IndexHints{Type: ForceStr, Indexes: $4}
  }

index_list:
  sql_id
  {
    $$ = []ColIdent{$1}
  }
| index_list ',' sql_id
  {
    $$ = append($1, $3)
  }

where_expression_opt:
  {
    $$ = nil
  }
| WHERE expression
  {
    $$ = $2
  }

expression:
  condition
  {
    $$ = $1
  }
| expression AND expression
  {
    $$ = &AndExpr{Left: $1, Right: $3}
  }
| expression OR expression
  {
    $$ = &OrExpr{Left: $1, Right: $3}
  }
| NOT expression
  {
    $$ = &NotExpr{Expr: $2}
  }
| expression IS is_suffix
  {
    $$ = &IsExpr{Operator: $3, Expr: $1}
  }
| value_expression
  {
    $$ = $1
  }
| DEFAULT default_opt
  {
    $$ = &Default{ColName: $2}
  }

default_opt:
  /* empty */
  {
    $$ = ""
  }
| openb ID closeb
  {
    $$ = string($2)
  }

boolean_value:
  TRUE
  {
    $$ = BoolVal(true)
  }
| FALSE
  {
    $$ = BoolVal(false)
  }

condition:
  value_expression compare value_expression
  {
    $$ = &ComparisonExpr{Left: $1, Operator: $2, Right: $3}
  }
| value_expression IN col_tuple
  {
    $$ = &ComparisonExpr{Left: $1, Operator: InStr, Right: $3}
  }
| value_expression NOT IN col_tuple
  {
    $$ = &ComparisonExpr{Left: $1, Operator: NotInStr, Right: $4}
  }
| value_expression LIKE value_expression like_escape_opt
  {
    $$ = &ComparisonExpr{Left: $1, Operator: LikeStr, Right: $3, Escape: $4}
  }
| value_expression NOT LIKE value_expression like_escape_opt
  {
    $$ = &ComparisonExpr{Left: $1, Operator: NotLikeStr, Right: $4, Escape: $5}
  }
| value_expression REGEXP value_expression
  {
    $$ = &ComparisonExpr{Left: $1, Operator: RegexpStr, Right: $3}
  }
| value_expression NOT REGEXP value_expression
  {
    $$ = &ComparisonExpr{Left: $1, Operator: NotRegexpStr, Right: $4}
  }
| value_expression BETWEEN value_expression AND value_expression
  {
    $$ = &RangeCond{Left: $1, Operator: BetweenStr, From: $3, To: $5}
  }
| value_expression NOT BETWEEN value_expression AND value_expression
  {
    $$ = &RangeCond{Left: $1, Operator: NotBetweenStr, From: $4, To: $6}
  }
| EXISTS subquery
  {
    $$ = &ExistsExpr{Subquery: $2}
  }

is_suffix:
  NULL
  {
    $$ = IsNullStr
  }
| NOT NULL
  {
    $$ = IsNotNullStr
  }
| TRUE
  {
    $$ = IsTrueStr
  }
| NOT TRUE
  {
    $$ = IsNotTrueStr
  }
| FALSE
  {
    $$ = IsFalseStr
  }
| NOT FALSE
  {
    $$ = IsNotFalseStr
  }

compare:
  '='
  {
    $$ = EqualStr
  }
| '<'
  {
    $$ = LessThanStr
  }
| '>'
  {
    $$ = GreaterThanStr
  }
| LE
  {
    $$ = LessEqualStr
  }
| GE
  {
    $$ = GreaterEqualStr
  }
| NE
  {
    $$ = NotEqualStr
  }
| NULL_SAFE_EQUAL
  {
    $$ = NullSafeEqualStr
  }

like_escape_opt:
  {
    $$ = nil
  }
| ESCAPE value_expression
  {
    $$ = $2
  }

col_tuple:
  row_tuple
  {
    $$ = $1
  }
| subquery
  {
    $$ = $1
  }
| LIST_ARG
  {
    $$ = ListArg($1)
  }

subquery:
  openb select_statement closeb
  {
    $$ = &Subquery{$2}
  }

expression_list:
  expression
  {
    $$ = Exprs{$1}
  }
| expression_list ',' expression
  {
    $$ = append($1, $3)
  }

value_expression:
  value
  {
    $$ = $1
  }
| boolean_value
  {
    $$ = $1
  }
| column_name
  {
    $$ = $1
  }
| tuple_expression
  {
    $$ = $1
  }
| subquery
  {
    $$ = $1
  }
| value_expression '&' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: BitAndStr, Right: $3}
  }
| value_expression '|' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: BitOrStr, Right: $3}
  }
| value_expression '^' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: BitXorStr, Right: $3}
  }
| value_expression '+' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: PlusStr, Right: $3}
  }
| value_expression '-' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: MinusStr, Right: $3}
  }
| value_expression '*' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: MultStr, Right: $3}
  }
| value_expression '/' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: DivStr, Right: $3}
  }
| value_expression DIV value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: IntDivStr, Right: $3}
  }
| value_expression '%' value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: ModStr, Right: $3}
  }
| value_expression MOD value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: ModStr, Right: $3}
  }
| value_expression SHIFT_LEFT value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: ShiftLeftStr, Right: $3}
  }
| value_expression SHIFT_RIGHT value_expression
  {
    $$ = &BinaryExpr{Left: $1, Operator: ShiftRightStr, Right: $3}
  }
| column_name JSON_EXTRACT_OP value
  {
    $$ = &BinaryExpr{Left: $1, Operator: JSONExtractOp, Right: $3}
  }
| column_name JSON_UNQUOTE_EXTRACT_OP value
  {
    $$ = &BinaryExpr{Left: $1, Operator: JSONUnquoteExtractOp, Right: $3}
  }
| value_expression COLLATE charset
  {
    $$ = &CollateExpr{Expr: $1, Charset: $3}
  }
| BINARY value_expression %prec UNARY
  {
    $$ = &UnaryExpr{Operator: BinaryStr, Expr: $2}
  }
| '+'  value_expression %prec UNARY
  {
    if num, ok := $2.(*SQLVal); ok && num.Type == IntVal {
      $$ = num
    } else {
      $$ = &UnaryExpr{Operator: UPlusStr, Expr: $2}
    }
  }
| '-'  value_expression %prec UNARY
  {
    if num, ok := $2.(*SQLVal); ok && num.Type == IntVal {
      // Handle double negative
      if num.Val[0] == '-' {
        num.Val = num.Val[1:]
        $$ = num
      } else {
        $$ = NewIntVal(append([]byte("-"), num.Val...))
      }
    } else {
      $$ = &UnaryExpr{Operator: UMinusStr, Expr: $2}
    }
  }
| '~'  value_expression
  {
    $$ = &UnaryExpr{Operator: TildaStr, Expr: $2}
  }
| '!' value_expression %prec UNARY
  {
    $$ = &UnaryExpr{Operator: BangStr, Expr: $2}
  }
| INTERVAL value_expression sql_id
  {
    // This rule prevents the usage of INTERVAL
    // as a function. If support is needed for that,
    // we'll need to revisit this. The solution
    // will be non-trivial because of grammar conflicts.
    $$ = &IntervalExpr{Expr: $2, Unit: $3}
  }
| function_call_generic
| function_call_keyword
| function_call_nonkeyword
| function_call_conflict

/*
  Regular function calls without special token or syntax, guaranteed to not
  introduce side effects due to being a simple identifier
*/
function_call_generic:
  sql_id openb select_expression_list_opt closeb
  {
    $$ = &FuncExpr{Name: $1, Exprs: $3}
  }
| sql_id openb DISTINCT select_expression_list closeb
  {
    $$ = &FuncExpr{Name: $1, Distinct: true, Exprs: $4}
  }
| table_id '.' reserved_sql_id openb select_expression_list_opt closeb
  {
    $$ = &FuncExpr{Qualifier: $1, Name: $3, Exprs: $5}
  }

/*
  Function calls using reserved keywords, with dedicated grammar rules
  as a result
*/
function_call_keyword:
  LEFT openb select_expression_list closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("left"), Exprs: $3}
  }
| RIGHT openb select_expression_list closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("right"), Exprs: $3}
  }
| CONVERT openb expression ',' convert_type closeb
  {
    $$ = &ConvertExpr{Expr: $3, Type: $5}
  }
| CAST openb expression AS convert_type closeb
  {
    $$ = &ConvertExpr{Expr: $3, Type: $5}
  }
| CONVERT openb expression USING charset closeb
  {
    $$ = &ConvertUsingExpr{Expr: $3, Type: $5}
  }
| MATCH openb select_expression_list closeb AGAINST openb value_expression match_option closeb
  {
  $$ = &MatchExpr{Columns: $3, Expr: $7, Option: $8}
  }
| GROUP_CONCAT openb distinct_opt select_expression_list order_by_opt separator_opt closeb
  {
    $$ = &GroupConcatExpr{Distinct: $3, Exprs: $4, OrderBy: $5, Separator: $6}
  }
| CASE expression_opt when_expression_list else_expression_opt END
  {
    $$ = &CaseExpr{Expr: $2, Whens: $3, Else: $4}
  }
| VALUES openb sql_id closeb
  {
    $$ = &ValuesFuncExpr{Name: $3}
  }

/*
  Function calls using non reserved keywords but with special syntax forms.
  Dedicated grammar rules are needed because of the special syntax
*/
function_call_nonkeyword:
  CURRENT_TIMESTAMP func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("current_timestamp")}
  }
| UTC_TIMESTAMP func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("utc_timestamp")}
  }
| UTC_TIME func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("utc_time")}
  }
| UTC_DATE func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("utc_date")}
  }
  // now
| LOCALTIME func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("localtime")}
  }
  // now
| LOCALTIMESTAMP func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("localtimestamp")}
  }
  // curdate
| CURRENT_DATE func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("current_date")}
  }
  // curtime
| CURRENT_TIME func_datetime_precision_opt
  {
    $$ = &FuncExpr{Name:NewColIdent("current_time")}
  }

func_datetime_precision_opt:
  /* empty */
| openb closeb

/*
  Function calls using non reserved keywords with *normal* syntax forms. Because
  the names are non-reserved, they need a dedicated rule so as not to conflict
*/
function_call_conflict:
  IF openb select_expression_list closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("if"), Exprs: $3}
  }
| DATABASE openb select_expression_list_opt closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("database"), Exprs: $3}
  }
| MOD openb select_expression_list closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("mod"), Exprs: $3}
  }
| REPLACE openb select_expression_list closeb
  {
    $$ = &FuncExpr{Name: NewColIdent("replace"), Exprs: $3}
  }

match_option:
/*empty*/
  {
    $$ = ""
  }
| IN BOOLEAN MODE
  {
    $$ = BooleanModeStr
  }
| IN NATURAL LANGUAGE MODE
 {
    $$ = NaturalLanguageModeStr
 }
| IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION
 {
    $$ = NaturalLanguageModeWithQueryExpansionStr
 }
| WITH QUERY EXPANSION
 {
    $$ = QueryExpansionStr
 }

charset:
  ID
{
    $$ = string($1)
}
| STRING
{
    $$ = string($1)
}

convert_type:
  BINARY length_opt
  {
    $$ = &ConvertType{Type: string($1), Length: $2}
  }
| CHAR length_opt charset_opt
  {
    $$ = &ConvertType{Type: string($1), Length: $2, Charset: $3, Operator: CharacterSetStr}
  }
| CHAR length_opt ID
  {
    $$ = &ConvertType{Type: string($1), Length: $2, Charset: string($3)}
  }
| DATE
  {
    $$ = &ConvertType{Type: string($1)}
  }
| DATETIME length_opt
  {
    $$ = &ConvertType{Type: string($1), Length: $2}
  }
| DECIMAL decimal_length_opt
  {
    $$ = &ConvertType{Type: string($1)}
    $$.Length = $2.Length
    $$.Scale = $2.Scale
  }
| JSON
  {
    $$ = &ConvertType{Type: string($1)}
  }
| NCHAR length_opt
  {
    $$ = &ConvertType{Type: string($1), Length: $2}
  }
| SIGNED
  {
    $$ = &ConvertType{Type: string($1)}
  }
| SIGNED INTEGER
  {
    $$ = &ConvertType{Type: string($1)}
  }
| TIME length_opt
  {
    $$ = &ConvertType{Type: string($1), Length: $2}
  }
| UNSIGNED
  {
    $$ = &ConvertType{Type: string($1)}
  }
| UNSIGNED INTEGER
  {
    $$ = &ConvertType{Type: string($1)}
  }

expression_opt:
  {
    $$ = nil
  }
| expression
  {
    $$ = $1
  }

separator_opt:
  {
    $$ = string("")
  }
| SEPARATOR STRING
  {
    $$ = " separator '"+string($2)+"'"
  }

when_expression_list:
  when_expression
  {
    $$ = []*When{$1}
  }
| when_expression_list when_expression
  {
    $$ = append($1, $2)
  }

when_expression:
  WHEN expression THEN expression
  {
    $$ = &When{Cond: $2, Val: $4}
  }

else_expression_opt:
  {
    $$ = nil
  }
| ELSE expression
  {
    $$ = $2
  }

column_name:
  sql_id
  {
    $$ = &ColName{Name: $1}
  }
| table_id '.' reserved_sql_id
  {
    $$ = &ColName{Qualifier: TableName{Name: $1}, Name: $3}
  }
| table_id '.' reserved_table_id '.' reserved_sql_id
  {
    $$ = &ColName{Qualifier: TableName{Qualifier: $1, Name: $3}, Name: $5}
  }

value:
  STRING
  {
    $$ = NewStrVal($1)
  }
| HEX
  {
    $$ = NewHexVal($1)
  }
| INTEGRAL
  {
    $$ = NewIntVal($1)
  }
| FLOAT
  {
    $$ = NewFloatVal($1)
  }
| HEXNUM
  {
    $$ = NewHexNum($1)
  }
| VALUE_ARG
  {
    $$ = NewValArg($1)
  }
| NULL
  {
    $$ = &NullVal{}
  }

num_val:
  sql_id
  {
    // TODO(sougou): Deprecate this construct.
    if $1.Lowered() != "value" {
      yylex.Error("expecting value after next")
      return 1
    }
    $$ = NewIntVal([]byte("1"))
  }
| INTEGRAL VALUES
  {
    $$ = NewIntVal($1)
  }
| VALUE_ARG VALUES
  {
    $$ = NewValArg($1)
  }

group_by_opt:
  {
    $$ = nil
  }
| GROUP BY expression_list
  {
    $$ = $3
  }

having_opt:
  {
    $$ = nil
  }
| HAVING expression
  {
    $$ = $2
  }

order_by_opt:
  {
    $$ = nil
  }
| ORDER BY order_list
  {
    $$ = $3
  }

order_list:
  order
  {
    $$ = OrderBy{$1}
  }
| order_list ',' order
  {
    $$ = append($1, $3)
  }

order:
  expression asc_desc_opt
  {
    $$ = &Order{Expr: $1, Direction: $2}
  }

asc_desc_opt:
  {
    $$ = AscScr
  }
| ASC
  {
    $$ = AscScr
  }
| DESC
  {
    $$ = DescScr
  }

limit_opt:
  {
    $$ = nil
  }
| LIMIT expression
  {
    $$ = &Limit{Rowcount: $2}
  }
| LIMIT expression ',' expression
  {
    $$ = &Limit{Offset: $2, Rowcount: $4}
  }
| LIMIT expression OFFSET expression
  {
    $$ = &Limit{Offset: $4, Rowcount: $2}
  }

lock_opt:
  {
    $$ = ""
  }
| FOR UPDATE
  {
    $$ = ForUpdateStr
  }
| LOCK IN SHARE MODE
  {
    $$ = ShareModeStr
  }

// insert_data expands all combinations into a single rule.
// This avoids a shift/reduce conflict while encountering the
// following two possible constructs:
// insert into t1(a, b) (select * from t2)
// insert into t1(select * from t2)
// Because the rules are together, the parser can keep shifting
// the tokens until it disambiguates a as sql_id and select as keyword.
insert_data:
  VALUES tuple_list
  {
    $$ = &Insert{Rows: $2}
  }
| select_statement
  {
    $$ = &Insert{Rows: $1}
  }
| openb select_statement closeb
  {
    // Drop the redundant parenthesis.
    $$ = &Insert{Rows: $2}
  }
| openb ins_column_list closeb VALUES tuple_list
  {
    $$ = &Insert{Columns: $2, Rows: $5}
  }
| openb ins_column_list closeb select_statement
  {
    $$ = &Insert{Columns: $2, Rows: $4}
  }
| openb ins_column_list closeb openb select_statement closeb
  {
    // Drop the redundant parenthesis.
    $$ = &Insert{Columns: $2, Rows: $5}
  }

ins_column_list:
  sql_id
  {
    $$ = Columns{$1}
  }
| sql_id '.' sql_id
  {
    $$ = Columns{$3}
  }
| ins_column_list ',' sql_id
  {
    $$ = append($$, $3)
  }
| ins_column_list ',' sql_id '.' sql_id
  {
    $$ = append($$, $5)
  }

on_dup_opt:
  {
    $$ = nil
  }
| ON DUPLICATE KEY UPDATE update_list
  {
    $$ = $5
  }

tuple_list:
  tuple_or_empty
  {
    $$ = Values{$1}
  }
| tuple_list ',' tuple_or_empty
  {
    $$ = append($1, $3)
  }

tuple_or_empty:
  row_tuple
  {
    $$ = $1
  }
| openb closeb
  {
    $$ = ValTuple{}
  }

row_tuple:
  openb expression_list closeb
  {
    $$ = ValTuple($2)
  }

tuple_expression:
  row_tuple
  {
    if len($1) == 1 {
      $$ = &ParenExpr{$1[0]}
    } else {
      $$ = $1
    }
  }

update_list:
  update_expression
  {
    $$ = UpdateExprs{$1}
  }
| update_list ',' update_expression
  {
    $$ = append($1, $3)
  }

update_expression:
  column_name '=' expression
  {
    $$ = &UpdateExpr{Name: $1, Expr: $3}
  }

for_from:
  FOR
| FROM

exists_opt:
  { $$ = 0 }
| IF EXISTS
  { $$ = 1 }

not_exists_opt:
  { $$ = 0 }
| IF NOT EXISTS
  { $$ = 1 }

ignore_opt:
  { $$ = "" }
| IGNORE
  { $$ = IgnoreStr }

non_rename_operation:
  ALTER
  { $$ = struct{}{} }
| AUTO_INCREMENT
  { $$ = struct{}{} }
| CHARACTER
  { $$ = struct{}{} }
| COMMENT_KEYWORD
  { $$ = struct{}{} }
| DEFAULT
  { $$ = struct{}{} }
| DROP
  { $$ = struct{}{} }
| ORDER
  { $$ = struct{}{} }
| CONVERT
  { $$ = struct{}{} }
| UNUSED
  { $$ = struct{}{} }
| ID
  { $$ = struct{}{} }

to_opt:
  { $$ = struct{}{} }
| TO
  { $$ = struct{}{} }
| AS
  { $$ = struct{}{} }

index_opt:
  INDEX
  { $$ = struct{}{} }
| KEY
  { $$ = struct{}{} }

sql_id:
  ID
  {
    $$ = NewColIdent(string($1))
  }
| non_reserved_keyword
  {
    $$ = NewColIdent(string($1))
  }

reserved_sql_id:
  sql_id
| reserved_keyword
  {
    $$ = NewColIdent(string($1))
  }

table_id:
  ID
  {
    $$ = NewTableIdent(string($1))
  }
| non_reserved_keyword
  {
    $$ = NewTableIdent(string($1))
  }

reserved_table_id:
  table_id
| reserved_keyword
  {
    $$ = NewTableIdent(string($1))
  }

/*
  These are not all necessarily reserved in MySQL, but some are.

  These are more importantly reserved because they may conflict with our grammar.
  If you want to move one that is not reserved in MySQL (i.e. ESCAPE) to the
  non_reserved_keywords, you'll need to deal with any conflicts.

  Sorted alphabetically
*/
reserved_keyword:
  AND
| AS
| ASC
| AUTO_INCREMENT
| BETWEEN
| BINARY
| BY
| CASE
| CHARACTER
| CHARSET
| COLLATE
| CONVERT
| CREATE
| CROSS
| CURRENT_DATE
| CURRENT_TIME
| CURRENT_TIMESTAMP
| DATABASE
| DATABASES
| DEFAULT
| DELETE
| DESC
| DESCRIBE
| DISTINCT
| DIV
| DROP
| ELSE
| END
| ENGINES
| ESCAPE
| EXISTS
| EXPLAIN
| FALSE
| FOR
| FORCE
| FROM
| GROUP
| HAVING
| IF
| IGNORE
| IN
| INDEX
| INNER
| INSERT
| INTERVAL
| INTO
| IS
| JOIN
| KEY
| LEFT
| LIKE
| LIMIT
| LOCALTIME
| LOCALTIMESTAMP
| LOCK
| MATCH
| MOD
| NATURAL
| NEXT // next should be doable as non-reserved, but is not due to the special `select next num_val` query that vitess supports
| NOT
| NULL
| ON
| OR
| ORDER
| OUTER
| QUERYZ
| PROCESSLIST
| REGEXP
| RENAME
| REPLACE
| RIGHT
| SELECT
| SEPARATOR
| SET
| SHOW
| STATUS
| STRAIGHT_JOIN
| TABLE
| TABLES
| THEN
| TO
| TRUE
| TXNZ
| UNION
| UNIQUE
| UPDATE
| USE
| USING
| UTC_DATE
| UTC_TIME
| UTC_TIMESTAMP
| VALUES
| VERSIONS
| WHEN
| WHERE

/*
  These are non-reserved Vitess, because they don't cause conflicts in the grammar.
  Some of them may be reserved in MySQL. The good news is we backtick quote them
  when we rewrite the query, so no issue should arise.

  Sorted alphabetically
*/
non_reserved_keyword:
  AGAINST
| BIGINT
| BIT
| BLOB
| BOOL
| CHAR
| COMMENT_KEYWORD
| DATE
| DATETIME
| DECIMAL
| DOUBLE
| DUPLICATE
| ENUM
| ENGINE
| EXPANSION
| FLOAT_TYPE
| INT
| INTEGER
| JSON
| LANGUAGE
| LAST_INSERT_ID
| LONGBLOB
| LONGTEXT
| MEDIUMBLOB
| MEDIUMINT
| MEDIUMTEXT
| MODE
| NCHAR
| NUMERIC
| OFFSET
| OPTIMIZE
| PRIMARY
| QUERY
| REAL
| REPAIR
| SHARE
| SIGNED
| SMALLINT
| TEXT
| TIME
| TIMESTAMP
| TINYBLOB
| TINYINT
| TINYTEXT
| TRUNCATE
| UNSIGNED
| UNUSED
| VARBINARY
| VARCHAR
| VIEW
| VITESS_KEYSPACES
| VITESS_SHARDS
| VSCHEMA_TABLES
| WITH
| YEAR
| ZEROFILL

openb:
  '('
  {
    if incNesting(yylex) {
      yylex.Error("max nesting level reached")
      return 1
    }
  }

closeb:
  ')'
  {
    decNesting(yylex)
  }

force_eof:
{
  forceEOF(yylex)
}

ddl_force_eof:
  {
    forceEOF(yylex)
  }
| openb
  {
    forceEOF(yylex)
  }
| reserved_sql_id
  {
    forceEOF(yylex)
  }