SQL Delete duplicate rows (all or distinct)

SQL Delete duplicate rows (all or distinct)
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Delete a duplicate row SELECT statement Use the all or distinct option to display all rows in the table that meet the criteria, or delete duplicate rows of data, default to all. When using the distinct option, only one row is reserved for all duplicate rows of data in the result set returned by select

We can also use it to get rid of duplicate data.

Combining two tables to remove duplicate data (mainly in table 2), we will get the following table:

A b

A 1

b 0

C 0

D 0

E 4

Select A,b from table 1 where a does (select a from table 2)

Union

Select A,b from Table 2

Distinct syntax

Select distinct "field name" from "Table name"

SQL UNION ALL syntax

Select COLUMN_NAME (s) from table_name1 UNION ALL SELECT COLUMN_NAME (s) from table_name2