How can I joining two tables with different column in SQL Server CE?
I have two tables:
Table Schedule
+-----+----------+------+
+ ID + Name + Type +
+-----+----------+------+
+ 1 + A + 1 +
+ 2 + B + 1 +
+ 3 + C + 2 +
+-----+----------+------+
Table Description
+-----+--------------------+
+ ID + Description +
+-----+--------------------+
+ 1 + A1 - XXXXX +
+-----+--------------------+
And what I want to get is the table like:
+-----+----------+-----------------+
+ ID + Name + Description +
+-----+----------+-----------------+
+ 1 + A + A1 - XXXXX +
+ 2 + B + - +
+ 3 + C + - +
+-----+----------+-----------------+
Where the Description
column should be filled in by -
when the ID is not on the Description
table.
I tried this code:
SELECT S.ID, D.Description
FROM Schedule AS S
INNER JOIN Description AS D
But resulted in:
+-----+----------+-----------------+
+ ID + Name + Description +
+-----+----------+-----------------+
+ 1 + A + A1 - XXXXX +
+ 2 + B + A1 - XXXXX +
+ 3 + C + A1 - XXXXX +
+-----+----------+-----------------+
And when I tried to give ON Clause:
SELECT S.ID, D.Description
FROM Schedule AS S
INNER JOIN Description AS D ON S.ID = D.ID
It just get the row where the ID
is on the Description
table, like:
+-----+----------+-----------------+
+ ID + Name + Description +
+-----+----------+-----------------+
+ 1 + A + A1 - XXXXX +
+-----+----------+-----------------+
How can I do that?
[UPDATE]
I tried this code and it works:
SELECT S.ID, S.Name, COALESCE (D.Description, '-') AS Description
FROM Schedule AS S
LEFT OUTER JOIN Description AS D ON S.ID = D.ID
But now, how can I add a WHERE clause on it (pls see table SCHEDULE
above)?
I tried:
SELECT S.ID, S.Name, COALESCE (D.Description, '-') AS Description
FROM Schedule AS S
LEFT OUTER JOIN Description AS D ON S.ID = D.ID AND S.Type = '1'
But still get the whole rows.
You need to use LEFT OUTER JOIN
to join the tables Schedule and Description on the key field ID. Also, use COALESCE
to replace NULL values in Description column with -
SELECT S.ID
, S.Name
, COALESCE (D.Description, '-') AS Description
FROM Schedule AS S
LEFT OUTER JOIN Description AS D
ON S.ID = D.ID
Tested in Microsoft SQL Server CE version 4.0.8482.1
You need add the WHERE
clause after the JOINs. If you are planning to having an ORDER BY
, it should come after the WHERE
clause.
SELECT S.ID
, S.Name
, COALESCE (D.Description, '-') AS Description
FROM Schedule AS S
LEFT OUTER JOIN Description AS D
ON S.ID = D.ID
WHERE (S.Type = 1)
Tested in Microsoft SQL Server CE version 4.0.8482.1