写一个sql的antlr4文件

以下是一个简单的SQL的ANTLR4文件，它可以解析SELECT语句：

grammar SQL;

/*
 * Lexer rules
 */

SELECT: 'SELECT';
FROM: 'FROM';
WHERE: 'WHERE';
AND: 'AND';
OR: 'OR';
NOT: 'NOT';
IN: 'IN';
LIKE: 'LIKE';
BETWEEN: 'BETWEEN';
IS: 'IS';
NULL: 'NULL';

ID: [a-zA-Z][a-zA-Z0-9_]*;
NUMBER: [0-9]+('.'[0-9]+)?;

LPAREN: '(';
RPAREN: ')';
COMMA: ',';
DOT: '.';

WS: [ \t\r\n]+ -> skip;

/*
 * Parser rules
 */

selectStatement: SELECT selectList FROM tableExpression (WHERE searchCondition)?;

selectList: selectItem (COMMA selectItem)*;

selectItem: ID DOT ID | ID;

tableExpression: ID;

searchCondition: searchCondition AND searchCondition
    | searchCondition OR searchCondition
    | NOT searchCondition
    | comparisonPredicate
    | inPredicate
    | likePredicate
    | betweenPredicate
    | IS NULL
    | LPAREN searchCondition RPAREN;

comparisonPredicate: valueExpression comparisonOperator valueExpression;

comparisonOperator: '=' | '<>' | '<' | '<=' | '>' | '>=';

valueExpression: ID | NUMBER;

inPredicate: valueExpression IN LPAREN (valueExpression (COMMA valueExpression)*)? RPAREN;

likePredicate: valueExpression LIKE STRING;

betweenPredicate: valueExpression BETWEEN valueExpression AND valueExpression;

STRING: '\'' (~'\'')* '\'';