查询数据库没有重复 [英] Query database without duplicate

问题描述

我有两个数据库表t1和t2，我想从第三个表t3到t1插入所有数据，而t1和t2都没有重复数据？请帮助



我的尝试：



Cherch理想的解决方案对于这个问题

i have two database tables t1 and t2 and i want to insert all data from a third table t3 to t1 without duplicate data already in both t1 and t2? Please help

What I have tried:

Cherch for ideal solution for this problem

推荐答案

假设所有3个表都有相同的字段，比如field1和field2，除了主键（如果有的话），

Assuming all the 3 tables have identical fields, say field1 and field2, except the primary keys if any,

INSERT INTO table1 (
SELECT * FROM table3 t3 WHERE NOT EXISTS (

(SELECT * FROM table1 t1 WHERE t1.field1=t3.field1 AND t1.field2=t3.field2) 
OR
(SELECT * FROM table2 t2 WHERE t2.field1=t3.field1 AND t2.field2=t3.field2)

))

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