SQL SQLite 的服务器脚本

Question

我需要为 SQL 服务器转换脚本，以便我可以将它们用于 SQLite。

脚本如下所示：

DECLARE @var1 int = (SELECT Id FROM Table1 WHERE id = 'val1')
DECLARE @var2 int  = (SELECT Id FROM Table2 WHERE id = 'val2')

IF NOT EXISTS(SELECT * FROM Table3 WHERE id_1 = @var1 and id_2 = @var2)
    INSERT INTO Table3(id_1, id_2) VALUES (@var1, @var2)
GO

IF NOT EXISTS(SELECT * FROM Table4 WHERE id ='val3')
    INSERT INTO Table4(id, desc) values ('111', 'new entry')
GO

在 SQLite 中执行这些脚本的最佳做法是什么？

Answer 1

SQLite 不支持变量。

您可以使用 returns 将 2 个变量的值作为列的 CTE：

WITH cte(var1, var2) AS (
  SELECT (SELECT Id FROM Table1 WHERE id = 'val1'), (SELECT Id FROM Table2 WHERE id = 'val2') 
)
INSERT INTO Table3(id_1, id_2) 
SELECT var1, var2
FROM cte 
WHERE NOT EXISTS (SELECT * FROM Table3 t3 INNER JOIN cte c ON t3.id_1 = c.var1 AND t3.id_2 = c.var2);

INSERT INTO Table4(id, `desc`) 
SELECT '111', 'new entry'
WHERE NOT EXISTS (SELECT * FROM Table4 WHERE id ='val3')

SQL SQLite 的服务器脚本

SQL Server script for SQLite

sql

sql-server

sqlite

sql-insert