I have a table in SQL Server with around of 300 columns. I want to create a stored procedure that replaces all the negative numbers with null.
The table has columns of type float, integer, nvarchar and so on.
I try to do it with T-SQL, but can't. Please could help me?.
Thanks.
EDIT:
I need a stored procedure that transforms all numeric columns to null if they are negative. The table is dynamic and may be increasing or decreasing the number of columns.
DECLARE #updateStatement AS VARCHAR(MAX)
SET #updateStatement = null
set #target_table =''
select * from systypes
select #updateStatement = COALESCE(#updateStatement+'UPDATE '+ #TARGET_TABLE+' SET '+c.name+ '= NULL WHERE' + c.name +' >0;' ,'UPDATE '+ #TARGET_TABLE +' SET '+c.name+ '= NULL WHERE' + c.name +' >0;' ) from syscolumns as c
inner join sysobjects as o on c.id= o.id
INNER JOIN systypes as t on c.xtype = t.xtype
where o.name= #TARGET_TABLE
AND T.name in('int','real','money','decimal')
select #updateStatement
--EXEC (#updateStatement)
You will need to add more to the where clause for T.name in () to hit all the data types you want. But this will query all the columns in 1 table #Target_Table then create update statements for each column in that table, if they are negative it will set the ALL ROWS for that column to null.
To make work uncomment out the EXEC(#UpdateStatement) THIS IS A REAL TERRIBLE IDEA, if you are dead set on doing this review your update statements
AND TAKE A BACKUP UP FIRST
EDIT*** THIS WILL NOT TAKE INTO ACCOUNT WEIRD FLOATING POINT MATH
Related
I am using MS SQL and created one Dynamic stored procedure:
ALTER Procedure [dbo].[sp_MTracking]
(
#OList varchar(MAX)
)
As
BEGIN TRY
SET NOCOUNT ON
DECLARE #SQL varchar(600)
SET #SQL = 'select os.X,os.Y from Table1 as os join Table2 as s on os.sID=s.sID where s.SCode IN ('+ #OList +')'
exec (#SQL)
END TRY
BEGIN CATCH
Execute sp_DB_ErrorInfo
Select -1 Result
END CATCH
GO
It is working properly, but I am getting x,y values in reverse order.
For example if I am passing 'scode1,scode2' as parameter, I am getting x,y values for scode1 in 2nd row and x,y values for scode2 as first row.
How can I fix this issue
Thanks
This is a bit long for a comment.
SQL tables and results sets represent unordered sets. There is no ordering, unless you explicitly use an ORDER BY clause.
Your query does not have an ORDER BY. Hence, you have no reason to expect the results in any particular order. In addition, the ordering may be different on different runs of the query. If you want the results in a particular order, add ORDER BY.
Probably the easiest way is to use charindex():
order by charindex(',' + s.code + ',' , ',''' + #olist + ''',')
This is a bit more cumbersome in dynamic sql:
SET #SQL = '
select os.X,os.Y
from Table1 os join
Table2 s
on os.sID = s.sID
where s.SCode IN (' + #OList + ')
order by charindex('','' + s.code + '','', '',''' + #OList + ''', '')
';
Well, there are a couple of things here.
The first thing is what Gordon wrote - to ensure the order of the result set you must use the order by clause.
Second, like Devart demonstrated in his answer, you don't need dynamic sql for this kind of procedures.
Third, if you want your results ordered by the order of the parameters in the list, you should use a slightly different approach then Devart wrote.
Therefor, here are my 2 cents:
If you can change the stored procedure to accept a table valued parameter instead of VARCHAR(max) that would be your best option IMHO.
If not, you must use a split function to create a table from that varchar and then use that table in your select.
Note that you will have to choose a split function that returns a table with two columns - one for the value and one for it's position in the original string.
Whatever the case may be, the rest of the sql should be something like this:
SELECT os.X, os.Y
FROM Table1 os
INNER JOIN Table2 s ON os.[sID] = s.[sID]
INNER JOIN #TVP t ON s.SCode = t.Value
ORDER BY t.Sort
That's assuming #TVP to be a Table containing a Value column that's the same data type of SCode in table2, and a Sort column (an int, naturally).
Without dynamic sql -
ALTER PROCEDURE [dbo].[sp_MTracking]
(
#OList VARCHAR(MAX)
)
AS BEGIN
SET NOCOUNT ON
DECLARE #t TABLE (val VARCHAR(50) PRIMARY KEY WITH(IGNORE_DUP_KEY=ON))
INSERT INTO #t
SELECT item = t.c.value('.', 'INT')
FROM (
SELECT txml = CAST('<r>' + REPLACE(#OList, ',', '</r><r>') + '</r>' AS XML)
) r
CROSS APPLY txml.nodes('/r') t(c)
SELECT os.X, os.Y
FROM Table1 os
JOIN Table2 s ON os.[sID] = s.[sID]
WHERE s.SCode IN (SELECT * FROM #t)
--OPTION(RECOMPILE)
END
GO
I am trying to figure out the best method to insert column names held in Table1 into a SELECT statement running against Table2. This query is running in a stored procedure. That doesn't do a very good job of explaining, so lets say I had these values in Table1:
What I am trying to do is use these column names in the SELECT statement against Table2:
Select -- Column Names
from Table2
where UserId = 3;
I'm not sure if an input parameter could be used in that way or how to pass the values into it. For example:
Select #ColumnNames
from Table2
where UserId = 3;
Or maybe a join to table 2?
Thanks!
You will have to use Dynamic SQL
declare #columns varchar(1000)
declare #sql varchar(8000)
select #columns='', #sql=''
select #columns=#columns+value+',' from table1
set #columns=left(#columns,len(#columns)-1)
set #sql='select '+#columns+' from table2'
exec(#sql)
But beware of SQL Injection and read www.sommarskog.se/dynamic_sql.html
You could query the system tables to get the column(s) i.e. (take out WHERE clause to see all the tables and columns)
SELECT tab.name AS TableName,
col.name AS ColName,
tp.name AS SType,
col.max_length,
col.[precision],
(CASE col.is_nullable
WHEN 1 THEN 'true'
WHEN 0 THEN 'false'
ELSE 'unknown'
END) AS Is_Nullable
FROM sys.tables as tab
LEFT OUTER JOIN sys.columns AS col
ON tab.object_id = col.object_id
LEFT OUTER JOIN sys.types AS tp
ON col.system_type_id = tp.system_type_id
WHERE tab.name = 'Table1'
ORDER BY tab.name,col.name
I'm trying to figure out a way to update a record without having to list every column name that needs to be updated.
For instance, it would be nice if I could use something similar to the following:
// the parts inside braces are what I am trying to figure out
UPDATE Employee
SET {all columns, without listing each of them}
WITH {this record with id of '111' from other table}
WHERE employee_id = '100'
If this can be done, what would be the most straightforward/efficient way of writing such a query?
It's not possible.
What you're trying to do is not part of SQL specification and is not supported by any database vendor. See the specifications of SQL UPDATE statements for MySQL, Postgresql, MSSQL, Oracle, Firebird, Teradata. Every one of those supports only below syntax:
UPDATE table_reference
SET column1 = {expression} [, column2 = {expression}] ...
[WHERE ...]
This is not posible, but..
you can doit:
begin tran
delete from table where CONDITION
insert into table select * from EqualDesingTabletoTable where CONDITION
commit tran
be carefoul with identity fields.
Here's a hardcore way to do it with SQL SERVER. Carefully consider security and integrity before you try it, though.
This uses schema to get the names of all the columns and then puts together a big update statement to update all columns except ID column, which it uses to join the tables.
This only works for a single column key, not composites.
usage: EXEC UPDATE_ALL 'source_table','destination_table','id_column'
CREATE PROCEDURE UPDATE_ALL
#SOURCE VARCHAR(100),
#DEST VARCHAR(100),
#ID VARCHAR(100)
AS
DECLARE #SQL VARCHAR(MAX) =
'UPDATE D SET ' +
-- Google 'for xml path stuff' This gets the rows from query results and
-- turns into comma separated list.
STUFF((SELECT ', D.'+ COLUMN_NAME + ' = S.' + COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = #DEST
AND COLUMN_NAME <> #ID
FOR XML PATH('')),1,1,'')
+ ' FROM ' + #SOURCE + ' S JOIN ' + #DEST + ' D ON S.' + #ID + ' = D.' + #ID
--SELECT #SQL
EXEC (#SQL)
In Oracle PL/SQL, you can use the following syntax:
DECLARE
r my_table%ROWTYPE;
BEGIN
r.a := 1;
r.b := 2;
...
UPDATE my_table
SET ROW = r
WHERE id = r.id;
END;
Of course that just moves the burden from the UPDATE statement to the record construction, but you might already have fetched the record from somewhere.
How about using Merge?
https://technet.microsoft.com/en-us/library/bb522522(v=sql.105).aspx
It gives you the ability to run Insert, Update, and Delete. One other piece of advice is if you're going to be updating a large data set with indexes, and the source subset is smaller than your target but both tables are very large, move the changes to a temporary table first. I tried to merge two tables that were nearly two million rows each and 20 records took 22 minutes. Once I moved the deltas over to a temp table, it took seconds.
If you are using Oracle, you can use rowtype
declare
var_x TABLE_A%ROWTYPE;
Begin
select * into var_x
from TABLE_B where rownum = 1;
update TABLE_A set row = var_x
where ID = var_x.ID;
end;
/
given that TABLE_A and TABLE_B are of same schema
It is possible. Like npe said it's not a standard practice. But if you really have to:
1. First a scalar function
CREATE FUNCTION [dte].[getCleanUpdateQuery] (#pTableName varchar(40), #pQueryFirstPart VARCHAR(200) = '', #pQueryLastPart VARCHAR(200) = '', #pIncludeCurVal BIT = 1)
RETURNS VARCHAR(8000) AS
BEGIN
DECLARE #pQuery VARCHAR(8000);
WITH cte_Temp
AS
(
SELECT
C.name
FROM SYS.COLUMNS AS C
INNER JOIN SYS.TABLES AS T ON T.object_id = C.object_id
WHERE T.name = #pTableName
)
SELECT #pQuery = (
CASE #pIncludeCurVal
WHEN 0 THEN
(
STUFF(
(SELECT ', ' + name + ' = ' + #pQueryFirstPart + #pQueryLastPart FROM cte_Temp FOR XML PATH('')), 1, 2, ''
)
)
ELSE
(
STUFF(
(SELECT ', ' + name + ' = ' + #pQueryFirstPart + name + #pQueryLastPart FROM cte_Temp FOR XML PATH('')), 1, 2, ''
)
) END)
RETURN 'UPDATE ' + #pTableName + ' SET ' + #pQuery
END
2. Use it like this
DECLARE #pQuery VARCHAR(8000) = dte.getCleanUpdateQuery(<your table name>, <query part before current value>, <query part after current value>, <1 if current value is used. 0 if updating everything to a static value>);
EXEC (#pQuery)
Example 1: make all employees columns 'Unknown' (you need to make sure column type matches the intended value:
DECLARE #pQuery VARCHAR(8000) = dte.getCleanUpdateQuery('employee', '', 'Unknown', 0);
EXEC (#pQuery)
Example 2: Remove an undesired text qualifier (e.g. #)
DECLARE #pQuery VARCHAR(8000) = dte.getCleanUpdateQuery('employee', 'REPLACE(', ', ''#'', '''')', 1);
EXEC (#pQuery)
This query can be improved. This is just the one I saved and sometime I use. You get the idea.
Similar to an upsert, you could check if the item exists on the table, if so, delete it and insert it with the new values (technically updating it) but you would lose your rowid if that's something sensitive to keep in your case.
Behold, the updelsert
IF NOT EXISTS (SELECT * FROM Employee WHERE ID = #SomeID)
INSERT INTO Employee VALUES(#SomeID, #Your, #Vals, #Here)
ELSE
DELETE FROM Employee WHERE ID = #SomeID
INSERT INTO Employee VALUES(#SomeID, #Your, #Vals, #Here)
you could do it by deleting the column in the table and adding the column back in and adding a default value of whatever you needed it to be. then saving this will require to rebuild the table
I have inherited a large database project with thousands of views.
Many of the views are invalid. They reference columns that no longer exist. Some of the views are very complex and reference many columns.
Is there an easy way to track down all the incorrect columns references?
This answer finds the underlying columns that were originally defined in the views by looking at sys.views, sys.columns and sys.depends (to get the underlying column if the column has been aliased). It then compares this with the data held in INFORMATION_Schema.VIEW_COLUMN_USAGE which appears to have the current column usage.
SELECT SCHEMA_NAME(v.schema_id) AS SchemaName,
OBJECT_NAME(v.object_id) AS ViewName,
COALESCE(alias.name, C.name) As MissingUnderlyingColumnName
FROM sys.views v
INNER JOIN sys.columns C
ON C.object_id = v.object_id
LEFT JOIN sys.sql_dependencies d
ON d.object_id = v.object_id
LEFT JOIN sys.columns alias
ON d.referenced_major_id = alias.object_id AND c.column_id= alias.column_id
WHERE NOT EXISTS
(
SELECT * FROM Information_Schema.VIEW_COLUMN_USAGE VC
WHERE VIEW_NAME = OBJECT_NAME(v.object_id)
AND VC.COLUMN_NAME = COALESCE(alias.name, C.name)
AND VC.TABLE_SCHEMA = SCHEMA_NAME(v.schema_id)
)
For the following view:
create table test
( column1 varchar(20), column2 varchar(30))
create view vwtest as select column1, column2 as column3 from test
alter table test drop column column1
The query returns:
SchemaName ViewName MissingUnderlyingColumnName
dbo vwtest column1
This was developed with the help of this Answer
UPDATED TO RETRIEVE ERROR DETAILS
So this answer gets you what you want but it isn't the greatest code.
A cursor is used (yes I know :)) to execute a SELECT from each view in a TRY block to find ones that fail. Note I wrap each statement with a SELECT * INTO #temp FROM view X WHERE 1 = 0 this is to stop the EXEC returning any results and the 1=0 is so that SQL Server can optimize the query so that it is in effect a NO-OP.
I then return a list of any views whose sql has failed.
I haven't performed lots of testing on this, but it appears to work. I would like to get rid of the execution of each SELECT from View.
So here it is:
DECLARE curView CURSOR FOR
SELECT v.name AS ViewName
FROM sys.views v
INNER JOIN sys.sql_modules m
on v.object_id = m.object_id
OPEN curView
DECLARE #viewName SYSNAME
DECLARE #failedViews TABLE
(
FailedViewName SYSNAME,
ErrorMessage VARCHAR(MAX)
)
FETCH NEXT FROM curView
INTO #ViewName
WHILE ##FETCH_STATUS = 0
BEGIN
BEGIN TRY
exec ('SELECT * INTO #temp FROM ' + #viewName + ' WHERE 1=0' )
END TRY
BEGIN CATCH
INSERT INTO #failedViews VALUES (#viewName, ERROR_MESSAGE())
END CATCH
FETCH NEXT FROM curView
INTO #ViewName
END
CLOSE curView
DEALLOCATE curView
SELECT *
FROM #failedViews
An example of an ERROR returned is:
FailedViewName ErrorMessage
--------------- -------------
vwtest Invalid column name 'column1'.
You could use system tables get information.
SELECT v.VIEW_NAME,v.TABLE_CATALOG,v.TABLE_SCHEMA,v.TABLE_NAME,v.COLUMN_NAME
from INFORMATION_SCHEMA.VIEW_COLUMN_USAGE v
left outer join INFORMATION_SCHEMA.COLUMNS c
ON v.TABLE_CATALOG=c.TABLE_CATALOG AND v.TABLE_SCHEMA=c.TABLE_SCHEMA AND v.TABLE_NAME=c.TABLE_NAME AND v.COLUMN_NAME=c.COLUMN_NAME
WHERE c.TABLE_NAME IS NULL
ORDER BY v.VIEW_NAME
I've been working on a project and came across some interesting behavior when using SELECT INTO. If I have a table with a column defined as int identity(1,1) not null and use SELECT INTO to copy it, the new table will retain the IDENTITY property unless there is a join involved. If there is a join, then the same column on the new table is defined simply as int not null.
Here is a script that you can run to reproduce the behavior:
CREATE TABLE People (Id INT IDENTITY(1,1) not null, Name VARCHAR(10))
CREATE TABLE ReverseNames (Name varchar(10), ReverseName varchar(10))
INSERT INTO People (Name)
VALUES ('John'), ('Jamie'), ('Joe'), ('Jenna')
INSERT INTO ReverseNames (Name, ReverseName)
VALUES ('John','nhoJ'), ('Jamie','eimaJ'), ('Joe','eoJ'), ('Jenna','anneJ')
--------
SELECT Id, Name
INTO People_ExactCopy
FROM People
SELECT Id, ReverseName as Name
INTO People_WithJoin
FROM People
JOIN ReverseNames
ON People.Name = ReverseNames.Name
SELECT Id, (SELECT ReverseName FROM ReverseNames WHERE Name = People.Name) as Name
INTO People_WithSubSelect
FROM People
--------
SELECT OBJECT_NAME(c.object_id) as [Table],
c.is_identity as [Id Column Retained Identity]
FROM sys.columns c
where
OBJECT_NAME(c.object_id) IN ('People_ExactCopy','People_WithJoin','People_WithSubSelect')
AND c.name = 'Id'
--------
DROP TABLE People
DROP TABLE People_ExactCopy
DROP TABLE People_WithJoin
DROP TABLE People_WithSubSelect
DROP TABLE ReverseNames
I noticed that the execution plans for both the WithJoin and WithSubSelect queries contained one join operator. I'm not sure if one will be significantly better on performance if we were dealing with a larger set of rows.
Can anyone shed any light on this and tell me if there is a way to utilize SELECT INTO with joins and still preserve the IDENTITY property?
From Microsoft:
When an existing identity column is
selected into a new table, the new
column inherits the IDENTITY property,
unless one of the following conditions
is true:
The SELECT statement contains a join, GROUP BY clause, or aggregate function.
Multiple SELECT statements are joined by using UNION.
The identity column is listed more than one time in the select list.
The identity column is part of an expression.
The identity column is from a remote data source.
If any one of these conditions is
true, the column is created NOT NULL
instead of inheriting the IDENTITY
property. If an identity column is
required in the new table but such a
column is not available, or you want a
seed or increment value that is
different than the source identity
column, define the column in the
select list using the IDENTITY
function.
You could use the IDENTITY function as they suggest and omit the IDENTITY column, but then you would lose the values, as the IDENTITY function would generate new values and I don't think that those are easily determinable, even with ORDER BY.
I don't believe there is much you can do, except build your CREATE TABLE statements manually, SET IDENTITY_INSERT ON, insert the existing values, then SET IDENTITY_INSERT OFF. Yes you lose the benefits of SELECT INTO, but unless your tables are huge and you are doing this a lot, [shrug]. This is not fun of course, and it's not as pretty or simple as SELECT INTO, but you can do it somewhat programmatically, assuming two tables, one having a simple identity (1,1), and a simple INNER JOIN:
SET NOCOUNT ON;
DECLARE
#NewTable SYSNAME = N'dbo.People_ExactCopy',
#JoinCondition NVARCHAR(255) = N' ON p.Name = r.Name';
DECLARE
#cols TABLE(t SYSNAME, c SYSNAME, p CHAR(1));
INSERT #cols SELECT N'dbo.People', N'Id', 'p'
UNION ALL SELECT N'dbo.ReverseNames', N'Name', 'r';
DECLARE #sql NVARCHAR(MAX) = N'CREATE TABLE ' + #NewTable + '
(
';
SELECT #sql += c.name + ' ' + t.name
+ CASE WHEN t.name LIKE '%char' THEN
'(' + CASE WHEN c.max_length = -1
THEN 'MAX' ELSE RTRIM(c.max_length/
(CASE WHEN t.name LIKE 'n%' THEN 2 ELSE 1 END)) END
+ ')' ELSE '' END
+ CASE c.is_identity
WHEN 1 THEN ' IDENTITY(1,1)'
ELSE ' ' END + ',
'
FROM sys.columns AS c
INNER JOIN #cols AS cols
ON c.object_id = OBJECT_ID(cols.t)
INNER JOIN sys.types AS t
ON c.system_type_id = t.system_type_id
AND c.name = cols.c;
SET #sql = LEFT(#sql, LEN(#sql)-1) + '
);
SET IDENTITY_INSERT ' + #NewTable + ' ON;
INSERT ' + #NewTable + '(';
SELECT #sql += c + ',' FROM #cols;
SET #sql = LEFT(#sql, LEN(#sql)-1) + ')
SELECT ';
SELECT #sql += p + '.' + c + ',' FROM #cols;
SET #sql = LEFT(#sql, LEN(#sql)-1) + '
FROM ';
SELECT #sql += t + ' AS ' + p + '
INNER JOIN ' FROM (SELECT DISTINCT
t,p FROM #cols) AS x;
SET #sql = LEFT(#sql, LEN(#sql)-10)
+ #JoinCondition + ';
SET IDENTITY_INSERT ' + #NewTable + ' OFF;';
PRINT #sql;
With the tables given above, this produces the following, which you could pass to EXEC sp_executeSQL instead of PRINT:
CREATE TABLE dbo.People_ExactCopy
(
Id int IDENTITY(1,1),
Name varchar(10)
);
SET IDENTITY_INSERT dbo.People_ExactCopy ON;
INSERT dbo.People_ExactCopy(Id,Name)
SELECT p.Id,r.Name
FROM dbo.People AS p
INNER JOIN dbo.ReverseNames AS r
ON p.Name = r.Name;
SET IDENTITY_INSERT dbo.People_ExactCopy OFF;
I did not deal with other complexities such as DECIMAL columns or other columns that have parameters such as max_length, nor did I deal with nullability, but these things wouldn't be hard to add it if you need greater flexibility.
In the next version of SQL Server (code-named "Denali") you should be able to construct a CREATE TABLE statement much easier using the new metadata discovery functions - which do much of the grunt work for you in terms of specifying precision/scale/length, dealing with MAX, etc. You still have to manually create indexes and constraints; but you don't get those with SELECT INTO either.
What we really need is DDL that allows you to say something like "CREATE TABLE a IDENTICAL TO b;" or "CREATE TABLE a BASED ON b;"... it's been asked for here, but has been rejected (this is about copying a table to another schema, but the same concept could apply to a new table in the same schema with a different table name). http://connect.microsoft.com/SQLServer/feedback/details/632689
I realize this is a really late response but whoever is still looking for this solution, like I was until I found this solution:
You can't use the JOIN operator for the IDENTITY column property to be inherited.
What you can do is use a WHERE clause like this:
SELECT a.*
INTO NewTable
FROM
MyTable a
WHERE
EXISTS (SELECT 1 FROM SecondTable b WHERE b.ID = a.ID)
This works.