/**
* @brief Visit the statement. This is the function that should be called in the first place.
* @param statement A SQL statement.
*/
public void visit(Statement statement) throws Exception {
if (statement instanceof Select) {
Select select = (Select) statement;
if (select.getWithItemsList() != null) {
for (WithItem withItem : ((Select) statement).getWithItemsList()) {
withItem.accept(this);
}
}
if (select.getSelectBody() != null) {
select.getSelectBody().accept(this);
}
} else if (statement instanceof DescribeTable) {
((DescribeTable) statement).accept(this);
}
// TODO: Add more type support here.
}
/**
* convert to order by sql
*
* @param sql
* @param orderBy
* @return
*/
public static String converToOrderBySql(String sql, String orderBy) {
// 解析SQL
Statement stmt = null;
try {
stmt = CCJSqlParserUtil.parse(sql);
Select select = (Select) stmt;
SelectBody selectBody = select.getSelectBody();
// 处理body-去最外层order by
List<OrderByElement> orderByElements = extraOrderBy(selectBody);
String defaultOrderBy = PlainSelect.orderByToString(orderByElements);
if (defaultOrderBy.indexOf('?') != -1) {
throw new RuntimeException("原SQL[" + sql + "]中的order by包含参数，因此不能使用OrderBy插件进行修改!");
}
// 新的sql
sql = select.toString();
} catch (Throwable e) {
e.printStackTrace();
}
return sql + " order by " + orderBy;
}
