refactor

sharding-jdbc-core/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlSelectParser.java

@@ -29,9 +29,6 @@ public class MySqlSelectParser extends AbstractSelectParser {
     
     @Override
     public void query() {
-        if (getExprParser().getLexer().equalToken(Token.LEFT_PAREN)) {
-            throw new UnsupportedOperationException("Cannot support subquery");
-        }
         if (getExprParser().getLexer().equalToken(Token.SELECT)) {
             getExprParser().getLexer().nextToken();
             while (getExprParser().getLexer().equalToken(Token.HINT) || getExprParser().getLexer().equalToken(Token.COMMENT)) {

sharding-jdbc-core/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleSelectParser.java

@@ -46,9 +46,6 @@ public class OracleSelectParser extends AbstractSelectParser {
     
     @Override
     public void query() {
-        if (getExprParser().getLexer().equalToken(Token.LEFT_PAREN)) {
-            throw new UnsupportedOperationException("Cannot support subquery");
-        }
         if (getExprParser().getLexer().equalToken(Token.SELECT)) {
             getExprParser().getLexer().nextToken();
             while (getExprParser().getLexer().equalToken(Token.HINT) || getExprParser().getLexer().equalToken(Token.COMMENT)) {

sharding-jdbc-core/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSelectParser.java

@@ -29,9 +29,6 @@ public class PGSelectParser extends AbstractSelectParser {
     
     @Override
     public void query() {
-        if (getExprParser().getLexer().equalToken(Token.LEFT_PAREN)) {
-            throw new UnsupportedOperationException("Cannot support subquery");
-        }
         if (getExprParser().getLexer().skipIfEqual(Token.SELECT)) {
             getExprParser().getLexer().skipIfEqual(Token.COMMENT);
             parseDistinct();

sharding-jdbc-core/src/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerSelectParser.java

@@ -40,9 +40,6 @@ public class SQLServerSelectParser extends AbstractSelectParser {
     
     @Override
     public void query() {
-        if (getExprParser().getLexer().equalToken(Token.LEFT_PAREN)) {
-            throw new UnsupportedOperationException("Cannot support subquery");
-        }
         SQLServerSelectQueryBlock queryBlock = new SQLServerSelectQueryBlock();
         if (getExprParser().getLexer().equalToken(Token.SELECT)) {
             getExprParser().getLexer().nextToken();

sharding-jdbc-core/src/main/java/com/alibaba/druid/sql/parser/AbstractSelectParser.java

@@ -68,9 +68,6 @@ public abstract class AbstractSelectParser {
     }
     
     protected void query() {
-        if (getExprParser().getLexer().equalToken(Token.LEFT_PAREN)) {
-            throw new UnsupportedOperationException("Cannot support subquery");
-        }
         getExprParser().getLexer().accept(Token.SELECT);
         getExprParser().getLexer().skipIfEqual(Token.COMMENT);
         parseDistinct();