Question

我的语法有问题。我需要在sqlite中使用IF，我替换IF - CASE 我的陈述不起作用，我不知道，有什么不对？

CASE
WHEN EXISTS
(SELECT sql FROM sqlite_master WHERE name = 'TEST_TABLE' AND type = 'table' AND sql LIKE '%aaaa%')
THEN
INSERT INTO atabela_new(id, idMain, idHistory, aNew) SELECT id, idMain, idHistory, aNew  FROM a_tabela
ELSE
INSERT INTO atabela_new(id, idMain, idHistory) SELECT id, idMain, idHistory FROM a_tabela;

Answer 1

假设aNew的默认值为NULL：

INSERT INTO atabela_new(id, idMain, idHistory, aNew)
SELECT id, 
       idMain, 
       idHistory,  
       CASE
           WHEN EXISTS
              (SELECT sql FROM sqlite_master WHERE name = 'TEST_TABLE' AND type = 'table' AND sql LIKE '%aaaa%')
           THEN aNew 
           ELSE NULL
       END
FROM a_tabela

否则，您需要将该逻辑放在应用程序代码中。

Answer 2

如果您要做的只是插入一条语句（如果为true）或另一条语句（如果为false），为什么不使用if语句呢？

IF EXISTS(SELECT sql FROM sqlite_master WHERE name = 'TEST_TABLE' AND type = 'table' AND sql LIKE '%aaaa%')
BEGIN
    INSERT INTO atabela_new(id, idMain, idHistory, aNew) SELECT id, idMain, idHistory, aNew FROM a_tabela
END
ELSE
    INSERT INTO atabela_new(id, idMain, idHistory) SELECT id, idMain, idHistory FROM a_tabela;
END

INSERT INTO使用CASE - sqlite？

2 个答案: