I'm trying to use an update statement using a combination of unique keys. These unique key are used in the where clause which are dragged from a select query using a sub query. Not sure how to use these two together.
Query looks something like this
1 UPDATE table1
2 SET column1 = .. , column2 = ..
3 WHERE TOOL_NO, TOOL_SERIAL_NO IN
4 (SELECT TOOL_NO, TOOL_SERIAL_NO FROM TABLE2 WHERE condition)
TOOL_NO and TOOL_SERIAL_NO are the unique keys and are dependent on each other.
For example Tool_No will have multiple Tool_Serial_No.
The problem is with line number 3. Not sure how to use two fields in the same where clause which depends on the same sub - query,
Any help is appreciated.
You're quite close - just enclose those columns in line #3 into brackets:
UPDATE table1
SET column1 = .. , column2 = ..
WHERE (TOOL_NO, TOOL_SERIAL_NO) IN
(SELECT TOOL_NO, TOOL_SERIAL_NO FROM TABLE2 WHERE condition)
You will also need to correlate the sub query against table2 with the outer where in table1 SQL.
While matching multiple columns in where clause together always enclose it into brackets. So in your case WHERE TOOL_NO, TOOL_SERIAL_NO should be WHERE (TOOL_NO, TOOL_SERIAL_NO)
UPDATE table1
SET column1 = .. , column2 = ..
WHERE (TOOL_NO, TOOL_SERIAL_NO) IN
(SELECT TOOL_NO, TOOL_SERIAL_NO FROM TABLE2 WHERE condition)
Related
I am trying to execute a query which is something like:
update table set column=(select column1 from table1);
I just want to store the value from other table to my column
but when i try my sql query it says
ERROR 1242 (21000): Subquery returns more than 1 row
definitely this means my table1 contains more than 1 row so i want to know that is there any way to store data into column from other table with multiple row.
or basically saving content of other table as a text something like
update table set column='Data in text from other table';
You probably need a correlation clause:
update table
set column = (select column1 from table1 where table.col = table1.col);
You need to decide what column(s) are used for the correlation.
it will work as i am getting your requirement.Please let me know if your requirement is other i ll make changes in query
update table_name t1
inner join table1 t2 on t1.id =t2.id
set column =column1
Your nested query returns multiple rows so you encountered this error.
Try in this way
UPDATE FirstTable
SET FirstTable.ColumnName =tbl2.ColumnName
FROM SecondTable tbl2 WHERE tbl2.Id = FirstTable.Id
There should be a common id or something that will help to find exact row.
I have two tables in my SQLite Database (dummy names):
Table 1: FileID F_Property1 F_Property2 ...
Table 2: PointID ForeignKey(fileid) P_Property1 P_Property2 ...
The entries in Table2 all have a foreign key column that references an entry in Table1.
I now would like to select entries from Table2 where for example F_Property1 of the referenced file in Table1 has a specific value.
I tried something naive:
select * from Table2 where fileid=(select FileID from Table1 where F_Property1 > 1)
Now this actually works..kind of. It selects a correct file id from Table1 and returns entries from Table2 with this ID. But it only uses the first returned ID. What I need it to do is basically connect the returned IDs from the inner select by OR so it returns data for all the IDs.
How can I do this? I think it is some kind of cross-table-query like what is asked here What is the proper syntax for a cross-table SQL query? but these answers contain no explaination of what they are actually doing so I'm struggeling with any implementation.
They are using JOIN statements, but wouldn't this mix entries from Table1 and Table2 together while only checking matching IDs in both tables? At least that is how I understand this http://www.codeproject.com/Articles/33052/Visual-Representation-of-SQL-Joins
As you may have noticed from the style, I'm very new to using databases in general, so please forgive me if not everything is clear about what I want. Please leave a comment and I will try to improve the question if neccessary.
The = operator compares a single value against another, so it is assumed that the subquery returns only a single row.
To check whether a (column) value is in a set of values, use IN:
SELECT *
FROM Table2
WHERE fileid IN (SELECT FileID
FROM Table1
WHERE F_Property1 > 1)
The way joins work is not by "mixing" the data, but sort of combining them based on the key.
In your case (I am assuming the key field in Table 1 is unique), if you join those two tables on the primary key field, you will end up with all the entries in table2 plus all corresponding fields from table1. If you were doing this:
select * from table1, table2 where table1.fieldID=table2.foreignkey;
then, providing your key fields are set up right, you will end up with the following:
PointID ForeignKey(fileid) P_Property1 P_Property2 FileID F_Property1 F_Property2
The field values from table1 would be from matching rows.
Now, if you do this:
select table1.* from table 1, table2 where
table1.fieldID=table2.foreignkey and F_Property1>1;
Would essentially get the same set of records, but will only show the columns from the second table, and only those that satisfy the where condition for the first one.
Hope this helps :)
If I understood your question correctly this will get the job done.
Select t2.*
from table1 t1
inner join table2 t2 on t2.id = t1.id
where t1.Prop = 'SomeValue'
I am trying to insert some data from one table into another but I would like to prevent the insertion of duplicate rows. I have currently the following query:
INSERT INTO Table1
(
Table1Col1,
Table1Col2,
Table1Col3,
Table1Col4,
Table1Col5
)
SELECT
Table2Col1,
Table2Col2 = constant1,
Table2Col3 = constant2,
Table2Col4 = constant3,
Table2Col5 = constant4
FROM Table2
WHERE
Condition1 = constant5
AND
Condition2 = constant6
AND
Condition3 = constant7
AND
Condition4 LIKE '%constant8%'
What I do not know is that the row I am trying to insert from Table2 into Table1 might already exist and I would like to prevent this possible duplication from happening and skip the insertion and just move onto inserting the next unique row.
I have seen that I can use a WHERE NOT EXISTS clause and use of the INTERSECT keyword but I did not fully understand how to apply it to my particular query as I only want to use some of the selected data from Table2 and then some constant values to insert into Table1.
EDIT:
I should add that the columns TableCol2 through to TableCol5 don't actually exist in the result set and I am just populating these columns alongside Table2Col1 that is returned.
Since you are on SQL Server 2008, you can use a merge statement.
You can easily check if a row exists base on a key
something like this:
merge TableMain AS target
using TableA as source
ON <join tables here>
WHEN MATCHED THEN <update>
WHEN NOT MATCHED BY TARGET <Insert>
WHEN NOT MATCHED BY SOURCE <delete>
Intersect (minus in Sql Server's terms) is out of question because it compares whole row. Other two options are not in/not exists/left join and merge. Not In is for single-column prinary key only, so it is out of question in this instance. In/Exists/Left join should have the same performance in Sql Server, so I'll just use exists:
INSERT INTO Table1
(
Table1Col1,
Table1Col2,
Table1Col3,
Table1Col4,
Table1Col5
)
SELECT
Table2Col1,
Table2Col2 = constant1,
Table2Col3 = constant2,
Table2Col4 = constant3,
Table2Col5 = constant4
FROM Table2
WHERE
Condition1 = constant5
AND
Condition2 = constant6
AND
Condition3 = constant7
AND
Condition4 LIKE '%constant8%'
AND NOT EXISTS
(
SELECT *
FROM Table1 target
WHERE target.Table1Col1 = Table2.Table2Col1
AND target.Table1Col2 = Table2.Table2Col2
AND target.Table1Col3 = Table2.Table2Col3
)
Merge is used to sync two tables; it has ability to insert, update and delete records from target table.
merge into table1 as target
using table2 as source
on target.Table1Col1 = source.Table2Col1
AND target.Table1Col2 = source.Table2Col2
AND target.Table1Col3 = source.Table2Col3
when not matched by target then
insert (Table1Col1,
Table1Col2,
Table1Col3,
Table1Col4,
Table1Col5)
values (Table2Col1,
Table2Col2,
Table2Col3,
Table2Col4,
Table2Col5);
If columns from table2 are computed during transfer, in not exists() case you might use derived table in place of table2, and the same applies to merge example - just place your query in place of reference to table2.
we have check the whether the data is already exist or not in table. For this we have to use If condition to avoid the duplicate insertion
I have a table that I need to Update by adding a new field.. I can alter the table and update each row . but is there a way of appending the result of a query to the table? ( I know that the result will have the same number of rows)
EDIT: So let me make it clear
I have
table1 | col1,col2
I generate another single column table
table2 | col1
I want
table3 | table1.col1,table1.col2,table2.col1
By the way table1 & table2 have no common fields so I cant join them meaningfully.
I think so. I haven't tested this, but what I can find it seems that you can use a SubQuery to do something along the lines of
UPDATE Table1 SET Column1 = Column1 & (SELECT Column2 FROM Table2 WHERE xxxx)
I am attempting to use a case statement but keep getting errors. Here's the statement:
select TABLE1.acct,
CASE
WHEN TABLE1.acct_id in (select acct_id
from TABLE2
group by acct_id
having count(*) = 1 ) THEN
(select name
from TABLE3
where TABLE1.acct_id = TABLE3.acct_id)
ELSE 'All Others'
END as Name
from TABLE1
When I replace the TABLE1.acct_id in the THEN expression with a literal value, the query works. When I try to use TABLE1.acct_id from the WHEN part of the query, I get a error saying the result is more than one row. It seems like the THEN expression is ignoring the single value that the WHEN statement was using. No idea, maybe this isn't even a valid use of the CASE statement.
I am trying to see names for accounts that have one entry in TABLE2.
Any ideas would be appreciated, I'm kind of new at SQL.
First, you are missing a comma after TABLE1.acct. Second, you have aliased TABLE1 as acct, so you should use that.
Select acct.acct
, Case
When acct.acct_id in ( Select acct_id
From TABLE2
Group By acct_id
Having Count(*) = 1 )
Then ( Select name
From TABLE3
Where acct.acct_id = TABLE3.acct_id
Fetch First 1 Rows Only)
Else 'All Others'
End as Name
From TABLE1 As acct
As others have said, you should adjust your THEN clause to ensure that only one value is returned. You can do that by add Fetch First 1 Rows Only to your subquery.
Then ( Select name
From TABLE3
Where acct.acct_id = TABLE3.acct_id
Fetch First 1 Rows Only)
Fetch is not accepting in CASE statement - "Keyword FETCH not expected. Valid tokens: ) UNION EXCEPT. "
select name from TABLE3 where TABLE1.acct_id = TABLE3.acct_id
will give you all the names in Table3, which have a accompanying row in Table 1. The row selected from Table2 in the previous line doesn't enter into it.
Must be getting more than one value.
You can replace the body with...
(select count(name) from TABLE3 where TABLE1.acct_id = TABLE3.acct_id)
... to narrow down which rows are returning multiples.
It may be the case that you just need a DISTINCT or a TOP 1 to reduce your result set.
Good luck!
I think that what is happening here is that your case must return a single value because it will be the value for the "name" column. The subquery (select acct_id from TABLE2 group by acct_id having count(*) = 1 ) is OK because it will only ever return one value. (select name from TABLE3 where TABLE1.acct_id= TABLE3.acct_id) could return multiple values depending on your data. The problem is you trying to shove multiple values into a single field for a single row.
The next thing to do would be to find out what data causes multiple rows to be returned by (select name from TABLE3 where TABLE1.acct_id= TABLE3.acct_id), and see if you can further limit this query to only return one row. If need be, you could even try something like ...AND ROWNUM = 1 (for Oracle - other DBs have similar ways of limiting rows returned).