Introduction of Background-4 and adding and modifying functions
In the processing of data, we often use is to delete the change. Next, let's talk about MySQL's incremental deletions. Check is our total use of the Select, here is introduced.
Add a row of data. Insert
Simple example
Insert into users values (' + ', ' Lcamry ', ' Lcamry ');
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Delete
? 2. Delete data:??
Delete?from. Table name;??
Delete?from? table name where?id=1;??
? Delete structure:??
Delete database: drop?database database name;??
Delete table: drop?table table name;??
to delete a column from a table: alter?table? table name? drop?column name;
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Simple example:
Delete from users where id=16
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Modify
? Modify all: Updata? Table name? set column name = ' new value, non-numeric plus single quote '?;??
? Modified with conditions: Updata table name? set column name = ' new value, non-numeric plus single quote '? where?id=6;??
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Update users set username= ' TT ' where id=15
MySQL injected into the Heavenly Book database additions and deletions introduced