How to write a SQL DELETE statement with a SELECT

问题:

Database: Sybase Advantage 11

On my quest to normalize data, I am trying to delete the results I get from this SELECT statement:

SELECT tableA.entitynum
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date')
;

This is the DELETE statement I have come up with:

DELETE FROM tableA
WHERE (SELECT q.entitynum
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date'))
;

I continuously get this error when I try to run this statement:

ERROR IN SCRIPT: poQuery: Error 7200:  AQE Error:  State = S0000;   NativeError = 2124;
[iAnywhere Solutions][Advantage SQL Engine]Invalid operand for operator: = Boolean value
cannot be operated with non-Boolean value.

I have also tried this statement:

DELETE FROM tableA 
INNER JOIN tableB u on (u.qlabel = tableA.entityrole AND u.fieldnum = tableA.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR tableA.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date')
;

Which results in:

ERROR IN SCRIPT: poQuery: Error 7200:  AQE Error:  State = 42000;   NativeError = 2117;
[iAnywhere Solutions][Advantage SQL Engine] Unexpected token: INNER -- Expecting semicolon.
-- Location of error in the SQL statement is: 23 (line: 2 column: 1)

Could someone aid me in properly constructing a DELETE query that will result in the proper data being removed?

回答1:

You need to identify the primary key in TableA in order to delete the correct record. The primary key may be a single column or a combination of several columns that uniquely identifies a row in the table. If there is no primary key, then the ROWID pseudo column may be used as the primary key.

DELETE FROM tableA
WHERE ROWID IN 
  ( SELECT q.ROWID
    FROM tableA q
      INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
    WHERE (LENGTH(q.memotext) NOT IN (8,9,10) OR q.memotext NOT LIKE '%/%/%')
      AND (u.FldFormat = 'Date'));

回答2:

Shouldn't you have:

DELETE FROM tableA WHERE entitynum IN (...your select...)

Now you just have a WHERE with no comparison:

DELETE FROM tableA WHERE (...your select...)

So your final query would look like this;

DELETE FROM tableA WHERE entitynum IN (
    SELECT tableA.entitynum FROM tableA q
      INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
    WHERE (LENGTH(q.memotext) NOT IN (8,9,10) OR q.memotext NOT LIKE '%/%/%')
      AND (u.FldFormat = 'Date')
)

回答3:

I tweaked your 2nd query to make it work. I think this is more straightforward than using a nested SELECT statement like in the other answers.

DELETE q
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date')

More detail here:
How to Delete using INNER JOIN with SQL Server?

回答4:

in this scenario:

DELETE FROM tableA
WHERE (SELECT q.entitynum
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date'));

aren't you missing the column you want to compare to? example:

DELETE FROM tableA
WHERE entitynum in (SELECT q.entitynum
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date'));    

I assume it's that column since in your select statement you're selecting from the same table you're wanting to delete from with that column.

回答5:

Did something like that once:

CREATE TABLE exclusions(excl VARCHAR(250));
INSERT INTO exclusions(excl)
VALUES
       ('%timeline%'),
       ('%Placeholders%'),
       ('%Stages%'),
       ('%master_stage_1205x465%'),
       ('%Accessories%'),
       ('%chosen-sprite.png'),
('%WebResource.axd');
GO
CREATE VIEW ToBeDeleted AS 
SELECT * FROM chunks
       WHERE chunks.file_id IN
       (
       SELECT DISTINCT
             lf.file_id
       FROM LargeFiles lf
       WHERE lf.file_id NOT IN
             (
             SELECT DISTINCT
                    lf.file_id
             FROM LargeFiles lf
                LEFT JOIN exclusions e ON(lf.URL LIKE e.excl)
                WHERE e.excl IS NULL
             )
       );
GO
CHECKPOINT
GO
SET NOCOUNT ON;
DECLARE @r INT;
SET @r = 1;
WHILE @r>0

BEGIN
    DELETE TOP (10000) FROM ToBeDeleted;
    SET @r = @@ROWCOUNT  
END
GO