放开对其他数据库的限制，可支持标准SQL

[terrymanu]

放开对Oracle，SQLServer，DB2，PostgreSQL等数据库的支持。
但只能识别标准SQL语句，对于个性化分页等语句并不支持。

[ivanhuang0757]

hello，I try to use sharding-jdbc1.3.0 to oralce11g,but it throw a exception.Is it support other database??can u tell m how to resolve this exception?

Exception in thread "main" java.lang.ClassCastException: com.dangdang.ddframe.rdb.sharding.parser.visitor.basic.mysql.MySQLSelectVisitor cannot be cast to com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor
at com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect.accept0(OracleSelect.java:58)
at com.alibaba.druid.sql.ast.SQLObjectImpl.accept(SQLObjectImpl.java:40)
at com.alibaba.druid.sql.visitor.SQLASTOutputVisitor.visit(SQLASTOutputVisitor.java:770)
at com.alibaba.druid.sql.ast.statement.SQLSelectStatement.accept0(SQLSelectStatement.java:58)
at com.alibaba.druid.sql.ast.SQLObjectImpl.accept(SQLObjectImpl.java:40)
at com.dangdang.ddframe.rdb.sharding.parser.SQLParseEngine.parse(SQLParseEngine.java:66)
at com.dangdang.ddframe.rdb.sharding.router.SQLRouteEngine.parseSQL(SQLRouteEngine.java:72)
at com.dangdang.ddframe.rdb.sharding.router.SQLRouteEngine.route(SQLRouteEngine.java:67)
at com.dangdang.ddframe.rdb.sharding.jdbc.ShardingPreparedStatement.routeSQL(ShardingPreparedStatement.java:165)
at com.dangdang.ddframe.rdb.sharding.jdbc.ShardingPreparedStatement.routeIfNeed(ShardingPreparedStatement.java:160)
at com.dangdang.ddframe.rdb.sharding.jdbc.ShardingPreparedStatement.getRoutedPreparedStatements(ShardingPreparedStatement.java:140)
at com.dangdang.ddframe.rdb.sharding.jdbc.ShardingPreparedStatement.executeQuery(ShardingPreparedStatement.java:95)
at com.dangdang.ddframe.rdb.sharding.example.jdbc.Main.printSimpleSelect(Main.java:60)
at com.dangdang.ddframe.rdb.sharding.example.jdbc.Main.main(Main.java:46)

[Cjie2000]

Only support MySQL