58 lines
1.5 KiB
Markdown
58 lines
1.5 KiB
Markdown
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DELETE statement deletes rows that satisfy the WHERE clause from the specified table. More about delete statement
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in PostgreSQL: https://www.postgresql.org/docs/11/sql-delete.html
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Following clauses are supported:
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- WHERE(delete_condition) - Only rows for which delete condition returns true will be deleted.
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- RETURNING(output_expression...) - An expressions to be computed and returned by the DELETE command after each row is deleted.
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The expression can use any column names of the table. Write _TableName_.AllColumns to return all columns.
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### Example
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```
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// delete all links with name 'Gmail' and 'Outlook'
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deleteStmt := Link.
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DELETE().
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WHERE(Link.Name.IN(String("Gmail"), String("Outlook")))
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```
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Debug sql of above statement:
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```sql
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DELETE FROM test_sample.link -- test_sample is name of the schema
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WHERE link.name IN ('Gmail', 'Outlook');
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```
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### Execute statement
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To execute delete statement and get sql.Result:
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```
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res, err := deleteStmt.Exec(db)
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```
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To execute delete statement and return records deleted,
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delete statement has to have RETURNING clause:
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```
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deleteStmt := Link.
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DELETE().
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WHERE(Link.Name.IN(String("Gmail"), String("Outlook"))).
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RETURNING(Link.AllColumns)
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dest := []model.Link{}
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err := deleteStmt.Query(db, &dest)
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```
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Use `ExecContext` and `QueryContext` to provide context object to execution.
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##### SQL table used for the example:
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```sql
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CREATE TABLE IF NOT EXISTS link (
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id serial PRIMARY KEY,
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url VARCHAR (255) NOT NULL,
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name VARCHAR (255) NOT NULL,
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description VARCHAR (255)
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);
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```
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