package com.alibaba.druid.sql.dialect.postgresql.parser;
import com.alibaba.druid.sql.ast.expr.SQLAggregateExpr;
import com.alibaba.druid.sql.dialect.postgresql.ast.PGAggregateExpr;
import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
import com.alibaba.druid.sql.dialect.postgresql.ast.expr.PGAnalytic;
import com.alibaba.druid.sql.parser.Lexer;
import com.alibaba.druid.sql.parser.ParserException;
import com.alibaba.druid.sql.parser.SQLExprParser;
import com.alibaba.druid.sql.parser.Token;
public class PGExprParser extends SQLExprParser{
public PGExprParser(String sql) throws ParserException{
super(sql);
}
public PGExprParser(Lexer lexer){
super(lexer);
}
protected SQLAggregateExpr parseAggregateExpr(String method_name) throws ParserException {
PGAggregateExpr aggregateExpr;
if (lexer.token() == Token.ALL) {
aggregateExpr = new PGAggregateExpr(method_name, 1);
lexer.nextToken();
} else if (lexer.token() == Token.DISTINCT) {
aggregateExpr = new PGAggregateExpr(method_name, 0);
lexer.nextToken();
} else {
aggregateExpr = new PGAggregateExpr(method_name, 1);
}
exprList(aggregateExpr.getArguments());
accept(Token.RPAREN);
if (lexer.token() == Token.OVER) {
lexer.nextToken();
PGAnalytic over = new PGAnalytic();
accept(Token.LPAREN);
if (identifierEquals("PARTITION")) {
lexer.nextToken();
accept(Token.BY);
if (lexer.token() == (Token.LPAREN)) {
lexer.nextToken();
exprList(over.getPartitionBy());
accept(Token.RPAREN);
} else {
exprList(over.getPartitionBy());
}
}
over.setOrderBy(parseOrderBy());
if (over.getOrderBy() != null) {
//TODO window
}
accept(Token.RPAREN);
aggregateExpr.setOver(over);
}
return aggregateExpr;
}
@Override
public PGOrderBy parseOrderBy() {
if (lexer.token() == (Token.ORDER)) {
PGOrderBy orderBy = new PGOrderBy();
lexer.nextToken();
if (identifierEquals("SIBLINGS")) {
lexer.nextToken();
orderBy.setSibings(true);
}
accept(Token.BY);
orderBy.getItems().add(parseSelectOrderByItem());
while (lexer.token() == (Token.COMMA)) {
lexer.nextToken();
orderBy.getItems().add(parseSelectOrderByItem());
}
return orderBy;
}
return null;
}
}