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Today, I will talk to you about how to use the SQL sentence insert to determine whether there is a record. Many people may not know much about it. In order to make you understand better, the editor has summarized the following content for you. I hope you can get something according to this article.

Judge whether there is a record INSERT INTO test (A _ Magi B) select 'ab',2 WHERE NOT EXISTS (SELECT * FROM test WHERE ab',2 WHERE NOT EXISTS) before sql statement insert; make a simple collection of judgments when sql is inserted

When inserting data when doing user modules or other modules that require the uniqueness of the database, you need to determine whether it already exists in the database.

The most basic insert statement of sql

```sql```sqlINSERT INTO user (name,password) values (admin,123456)

Next, it will be modified to insert to determine whether there is # {parameter}.

```sqlINSERT INTO user (name,password) SELECT # {admin}, # {123456} FROM DUAL WHERE NOT EXISTS (SELECT name,passwordFROM user WHERE name= # {admin} and password= # {123456}); ``

This is done. If the returned value of the query = 0 indicates failure = 1 indicates success

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