文档解释
ORA-25955: all tables must be joined in the where clause
Cause: An attempt to create a join index was made, which failed because one of the tables in the from clause did not appear in the where clause.
Action: Ensure that the where clause contains all from clause tables.
ORA-25955: all tables must be joined in the where clause 错误是指必须在Where语句中连接所有表才可以执行SQL查询。
官方解释
“This error occurs when a SQL query does not include all tables in the WHERE clause. Queries can join multiple tables in the same query. All tables must be joined together in the WHERE clause before a query can be executed. It is possible to use the “not-exists” statement in the WHERE clause to make it easier to join all tables.”
常见案例
在Oracle数据库中，当查询不在where语句中连接所有表或连接多表时，会发生ORA-25955错误。
一般处理方法及步骤
1）为查询的where块中的每个表添加一个连接表达式；
2）检查每个表之间的连接和关联是否准确；
3）确认查询中使用的字段是否来自连接表中的字段，不要使用未连接的字段；
4）确认每个表中都有实际数据（如果没有，此查询在where子句中不必连接这个表）；
5）重新设计查询，一次性连接所有表；
6）此外，既可以使用INNER JOIN语句来连接表，也可以使用NOT EXISTS语句。
