private static String[] getColumns(String sql) {
    String[] columnNames;
    try {
        SQLStatementParser sqlStatementParser = SQLParserUtils.createSQLStatementParser(sql, JdbcUtils.MYSQL);
        SQLStatement statement = sqlStatementParser.parseStatement();
        if (statement instanceof SQLSelectStatement) {
            SQLSelect select = ((SQLSelectStatement) statement).getSelect();
            com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock query = (com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock) select.getQuery();
            int size = query.getSelectList().size();
            if (size == 1){
                if("*".equalsIgnoreCase(   query.getSelectList().get(0).toString())){
                    throw new Exception("unsupport * in select items:"+sql);
                }
            } {
                columnNames = new String[size];
                for (int i = 0; i < size; i++) {
                    columnNames[i] = query.getSelectList().get(i).toString();
                }
                return columnNames;
            }

        }
    }catch (Exception e){
        LOGGER.error("can not get column count",e);
    }
    return new String[]{};
}
 

private void oracleValidationQueryCheck() {
    if (validationQuery == null) {
        return;
    }
    if (validationQuery.length() == 0) {
        return;
    }

    SQLStatementParser sqlStmtParser = SQLParserUtils.createSQLStatementParser(validationQuery, this.dbType);
    List<SQLStatement> stmtList = sqlStmtParser.parseStatementList();

    if (stmtList.size() != 1) {
        return;
    }

    SQLStatement stmt = stmtList.get(0);
    if (!(stmt instanceof SQLSelectStatement)) {
        return;
    }

    SQLSelectQuery query = ((SQLSelectStatement) stmt).getSelect().getQuery();
    if (query instanceof SQLSelectQueryBlock) {
        if (((SQLSelectQueryBlock) query).getFrom() == null) {
            LOG.error("invalid oracle validationQuery. " + validationQuery + ", may should be : " + validationQuery
                    + " FROM DUAL");
        }
    }
}
 

private void db2ValidationQueryCheck() {
    if (validationQuery == null) {
        return;
    }
    if (validationQuery.length() == 0) {
        return;
    }

    SQLStatementParser sqlStmtParser = SQLParserUtils.createSQLStatementParser(validationQuery, this.dbType);
    List<SQLStatement> stmtList = sqlStmtParser.parseStatementList();

    if (stmtList.size() != 1) {
        return;
    }

    SQLStatement stmt = stmtList.get(0);
    if (!(stmt instanceof SQLSelectStatement)) {
        return;
    }

    SQLSelectQuery query = ((SQLSelectStatement) stmt).getSelect().getQuery();
    if (query instanceof SQLSelectQueryBlock) {
        if (((SQLSelectQueryBlock) query).getFrom() == null) {
            LOG.error("invalid db2 validationQuery. " + validationQuery + ", may should be : " + validationQuery
                    + " FROM SYSDUMMY");
        }
    }
}
 

public static void sqlValid(String sql, DataBaseType dataBaseType){
    SQLStatementParser statementParser = SQLParserUtils.createSQLStatementParser(sql,dataBaseType.getTypeName());
    statementParser.parseStatementList();
}
 

private SQLStatement parseStmt(String sql) {
	SQLStatementParser statParser = SQLParserUtils.createSQLStatementParser(sql, "mysql");
	SQLStatement stmt = statParser.parseStatement();
	return stmt;		
}
 

private SQLStatement parseStmt(String sql) {
    SQLStatementParser statParser = SQLParserUtils.createSQLStatementParser(sql, "mysql");
    SQLStatement stmt = statParser.parseStatement();
    return stmt;
}