SQL插入到ColX表1从表2中选择ColY其中Table1.colA = Table2.ColB

Question

我比java开发人员更多的是java。我已经看着SO这一点，但由于某种原因，WHERE条件

在PostgreSQL，下面的语法不正确，无法找到类似的问题

INSERT INTO contentelementtypeprogressortype (contentelementtypeclassname) 
SELECT contentelementtypename FROM contentelementtype 
WHERE 
contentelementtype.id=contentelementtypeprogressortype.contentelementtypeid 

的错误是：

ERROR: invalid reference to FROM-clause entry for table "contentelementtypeprogressortype" LINE 2: ...OM contentelementtype where contentelementtype.id=contentele... ^ HINT: There is an entry for table "contentelementtypeprogressortype", but it cannot be referenced from this part of the query. ********** Error **********

ERROR: invalid reference to FROM-clause entry for table "contentelementtypeprogressortype" SQL state: 42P01 Hint: There is an entry for table "contentelementtypeprogressortype", but it cannot be referenced from this part of the query. Character: 159

Answer 1

这是你的查询：

INSERT INTO contentelementtypeprogressortype(contentelementtypeclassname) 
    SELECT cet.contentelementtypename 
    FROM contentelementtype cet 
    WHERE cet.id = contentelementtypeprogressortype.contentelementtypeid; 

我不认为你真的想要一个INSERT - 这增加了一个新的行。我想你真的想要一个UPDATE，它改变了现有的行中的值：

UPDATE contentelementtypeprogressortype cetpt 
    SET contentelementtypeclassname = cet.contentelementtypename 
    FROM contentelementtype cet 
    WHERE cet.id = cetpt.contentelementtypeid;