I have many tables, which names start with Lookup_. How can I alter column Name in every such table?
I am not quite sure what you want to do with Name, but this is how you change it to nvarchar(20).
Declare #sql as nvarchar(500)
Declare TableCursor CURSOR FAST_FORWARD FOR
SELECT 'alter table ' + table_schema + '.'+ table_name +' alter column name nvarchar(20)' FROM INFORMATION_SCHEMA.TABLES
WHERE left(table_name, 7) = 'lookup_' and table_type = 'BASE TABLE'
OPEN TableCursor
FETCH NEXT FROM TableCursor
INTO #sql
WHILE ##FETCH_STATUS = 0
BEGIN
EXEC (#sql)
FETCH NEXT FROM TableCursor
INTO #sql
END
CLOSE TableCursor
DEALLOCATE TableCursor
this looks much better
exec sp_msforeachtable
#command1 = 'alter table ? alter column name nvarchar(20)'
, #whereand = 'and left(o.name, 7) = ''lookup_'' and o.type = ''U'''
Related
SELECT TOP 10
*
FROM
(SELECT
COLUMN_NAME, TABLE_NAME
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
COLUMN_NAME LIKE '%MAIL%')
I am trying to get the top 10 rows from each of the tables within my search. Any ideas? SQL Server 2008 R2
While nscheaffer's answer is valid, I feel obligated to tell you that you can get the exact same functionality without using a cursor, and also while using a query which might be a bit easier to implement.
Just concatenate all of the possible queries together based off the system tables and then execute them simultaneously, like this:
DECLARE #SQL NVARCHAR(MAX)
;
SELECT #SQL =
(
SELECT 'SELECT TOP 10 * FROM ' + OBJECT_NAME(C.Object_ID) + ';' + CHAR(10)
FROM sys.Columns C
INNER JOIN sys.Tables T
ON C.Object_ID = T.Object_ID
AND T.is_ms_shipped = 0
WHERE C.Name LIKE '%Mail%'
GROUP BY C.Object_ID
ORDER BY C.Object_ID
FOR XML PATH('')
)
;
EXEC sp_ExecuteSQL #SQL
;
If you want to check the SQL before it runs, just comment out the EXEC command and replace it with a SELECT, like this:
SELECT #SQL;
--EXEC sp_ExecuteSQL #SQL
;
I would use a cursor to create dynamic SQL and then execute that SQL. Does this work for you?
DECLARE #SQL NVARCHAR (4000) = ''
DECLARE #Table_Name NVARCHAR(50)
DECLARE TableCursor CURSOR FAST_FORWARD READ_ONLY FOR
SELECT DISTINCT TABLE_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME LIKE '%MAIL%'
OPEN TableCursor
FETCH NEXT FROM TableCursor INTO #Table_Name
WHILE ##FETCH_STATUS = 0
BEGIN
SET #SQL = #SQL + '
SELECT TOP 10 * FROM ' + #Table_Name + '
GO
'
FETCH NEXT FROM TableCursor INTO #Table_Name
END
CLOSE TableCursor
DEALLOCATE TableCursor
EXECUTE sp_executeSQL #SQL
Our application does not delete data as we retain it for a period of time, instead we have a column "deleted" (bit) in most tables of the database that store data which we mark 1 when deleted, otherwise the default is 0.
I'd like to create a stored procedure that iterates all tables in the database, checks for the existence of a column named "deleted" and if it exists, I run a check against the LastUpdatedUtc column (datetime2) and if the date is over 6 months old and deleted = 1 then we delete the row.
This application is under continuous development so tables could be added which is why I want to create a script that iterates tables instead of having to add a line for each table and remember to add them as new tables are added.
Any help in a SQL Server 2008 R2 stored procedure to this would be a great help.
Thank you.
EDIT (thank you Omaer) here is what I've come up with so far. Anyone that knows a better way let me know.
IF OBJECT_ID('tempdb..#tmpTables') IS NOT NULL DROP TABLE #tmpTables
GO
CREATE TABLE #tmpTables
(
ID INT,
TableName NVARCHAR(100) NOT NULL
)
GO
SET NOCOUNT ON
GO
INSERT #tmpTables
SELECT [object_id], [name] FROM sys.all_objects WHERE type_desc = 'USER_TABLE' ORDER BY [name]
DECLARE #TN NVARCHAR(100)
DECLARE #SQL NVARCHAR(max)
DECLARE #PurgeDate VARCHAR(50)
SET #PurgeDate = DATEADD(MONTH, -6, GETUTCDATE())
WHILE (SELECT COUNT(*) FROM #tmpTables) > 0
BEGIN
SELECT TOP 1 #TN = TableName FROM #tmpTables
IF EXISTS(SELECT * FROM sys.columns WHERE name = 'deleted' AND OBJECT_ID = OBJECT_ID(#TN))
BEGIN
IF EXISTS(SELECT * FROM sys.columns WHERE name = 'LastUpdatedUtc' AND OBJECT_ID = OBJECT_ID(#TN))
BEGIN
SET #SQL = 'SELECT Count(*) As Counter FROM ' + #TN + ' WHERE [deleted] = 1 AND [LastUpdatedUtc] < ''' + #PurgeDate + '''' -- this will be the delete line when the code is final, just outputting results for now
EXEC(#SQL)
END
END
DELETE #tmpTables WHERE TableName=#TN
END
DROP TABLE #tmpTables
This is my first attempt, not tested it so there might be some typos/syntax errors but this should get you started:
declare #date6MonthsBack varchar(50)
select #date6MonthsBack = dateadd(month, -6, getdate());
declare c cursor for
select 'delete from ' + quotename(name) + ' where [deleted] = 1 and [LastUpdatedUtc] <= ''' + #date6MonthsBack + '''' from sys.tables
where object_id in (select object_id from sys.columns where name = 'deleted')
and object_id in (select object_id from sys.columns where name = 'LastUpdatedUtc')
declare #sql varchar(max)
open c; fetch next from c into #sql
while (##fetch_status = 0) begin
print(#sql)
--exec(#sql) --uncomment this line to do the actual deleting once you have verified the commands.
fetch next from c into #sql; end
close c; deallocate c
You could use undocummented sp_MSforeactable procedure instead of loop or cursor. Something like code below. I created procedure that runs your code and is executed with sp_MSforeachtable. The disadvantage is - the procedure is undocumented and may not be supported in next SQL Server releases
IF OBJECT_ID('dbo.usp_cleanup') IS NULL
EXEC ('CREATE PROCEDURE dbo.usp_cleanup AS SELECT 1')
GO
ALTER PROCEDURE dbo.usp_cleanup
#sTblName VARCHAR(200)
AS
BEGIN
-- your variables
DECLARE #PurgeDate VARCHAR(50)
DECLARE #SQL VARCHAR(MAX)
SET #PurgeDate = DATEADD(MONTH, -6, GETUTCDATE())
-- we can check columns existence in one condition
IF
EXISTS(SELECT * FROM sys.columns WHERE name = 'deleted' AND OBJECT_ID = OBJECT_ID(#sTblName))
AND EXISTS(SELECT * FROM sys.columns WHERE name = 'LastUpdatedUtc' AND OBJECT_ID = OBJECT_ID(#sTblName))
BEGIN
SET #SQL = 'SQL CODE GOES HERE' -- this will be the delete line when the code is final, just outputting results for now
PRINT #SQL
--EXEC(#SQL) -- uncomment for execution
END
ELSE
-- for debugging
BEGIN
PRINT #sTblName + ' has no [delete] and [LastUpdatedUtc] columns'
END
END
EXEC sp_MSforeachtable 'exec usp_cleanup ''?'''
GO
Using MS SQL2000 at present if that makes any difference.
Is there a better way than the method below to be able to programatically access a table ?
declare #tableName as varchar(50)
declare #sql varchar(4000)
set #tableName = 'User'
print #tableName
If EXISTS(
select TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE table_name = ''+#TableName+''
)
BEGIN
set #sql = 'select * from [' + #tableName + ']'
exec(#sql)
end
Essentially Im trying to create a simple Mapping tool for CRUD operations so that I need only one Sproc for each operation, and I can pass in my parameterised object, a table name and let the database do the rest. This is purely for my own personal education, hence why Im not using an established framework, so if there are any major gotcha's with my idea or the code above, I'd appreciate knowing as well.
Thanks
This is complete example to create a SP by follow your initial code:
CREATE PROCEDURE dbo.CustomSelect (#tableName as varchar(50))
AS
SET NOCOUNT ON
DECLARE #sql varchar(4000)
If EXISTS(
select TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE table_name = #tableName
)
BEGIN
set #sql = 'select 1 as Found, * from [' + #tableName + ']'
exec(#sql)
END
ELSE
BEGIN
select 0 as Found
END
This SP always return a recordset so you can check the value of the field FOUND to know if the table exist or not
usage:
EXEC CustomSelect 'User'
Hope it helps
I've been asked to create history tables for every table in a database. Then create a trigger that will write to the history table whenever the primary table is updated.
The history tables have the same structure as the primary table, but with a couple of extra rows ('id' and 'update type')
I've never done anything with triggers before, but I would like to do is dynamically go through the columns in 'Inserted' and construct an insert statement to populate the history table.
However I cannot work out how to read the names of the columns and their individual values.
My half finished trigger currently looks like...
CREATE TRIGGER tr_address_history
ON address
FOR UPDATE
AS
DECLARE #colCount int
DECLARE #maxCols int
SET #colCount = 0
SET #maxCols = (SELECT COUNT(column_name) FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME = 'Inserted')
PRINT 'Number of columns = ' + CONVERT(varChar(10),#maxCols)
WHILE (#colCount <= #maxCols)
BEGIN
DECLARE #name varchar(255)
SELECT #name = column_name FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME = 'Inserted'
DECLARE #value varchar(255)
SELECT #value = #name FROM Inserted
PRINT 'name = ' + #name + ' and value = ' + #value
SET #colCount = #colCount + 1
END
PRINT 'Done';
When the trigger runs it just says "Number of columns = 0"
Can anyone tell me what's wrong with :
SELECT COUNT(column_name) FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME = 'Inserted'
Thanks...
First solution proposed by Beenay25 is good, but you should use affected table instead of 'inserted' pseudotable.
This is:
SELECT #name = column_name FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME = 'AFFECTED_TABLE'
Instead of 'INSERTED'
Also, you should use dynamic SQL.
This will be a complete working solution:
ALTER TRIGGER [dbo].[tr_address_history]
ON [dbo].[address]
AFTER Insert
AS
DECLARE #ColumnName nvarchar(500)
DECLARE #TableName nvarchar(500)
DECLARE #value nvarchar(500)
DECLARE #Sql nvarchar(500)
Set #TableName='address'
DECLARE ColumnsCursor CURSOR FOR
select column_name FROM INFORMATION_SCHEMA.columns WHERE TABLE_NAME = 'address'
OPEN ColumnsCursor
FETCH NEXT FROM ColumnsCursor into #ColumnName
WHILE ##FETCH_STATUS=0
BEGIN
select * into #tmp from inserted
Set #Sql= 'SELECT #value =' + #ColumnName + ' FROM #tmp'
EXEC sp_executesql #Sql, N'#Value nvarchar(500) OUTPUT', #Value OUTPUT
DROP TABLE #TMP
print '[' + #ColumnName +'='+ ltrim(rtrim(#Value))+']'
FETCH NEXT FROM ColumnsCursor into #ColumnName
END
CLOSE ColumnsCursor
DEALLOCATE ColumnsCursor
The 'inserted' table is a pseudo-table; it doesn't appear in INFORMATION_SCHEMA.
There is the UPDATE() operator for use in triggers:
CREATE TRIGGER trigger_name ON tablename
FOR UPDATE
AS
SET NOCOUNT ON
IF (UPDATE(Column1) OR UPDATE(Column2))
BEGIN
your sql here
END
COLUMNS_UPDATED
UPDATE()
There is a way to do what the questioner requires:
I have made something inside a trigger that tests whether all the columns of a particular table actually participated in an insert to that table. If they did, I later copied them to a history table. If they did not, then rollback and print only complete rows may be inserted into the report table. Perhaps they could adapt this to their needs:
here it is:
[
if exists (select 1 from inserted) and not exists (select 1 from deleted) -- if an insert has been performed
begin -- and we want to test whether all the columns in the report table were included in the insert
declare #inserted_columncount int, #actual_num_of_columns int, #loop_columns int, #current_columnname nvarchar(300),
#sql_test nvarchar(max), #params nvarchar(max), #is_there bit
set #actual_num_of_columns = (
select count(*) from (
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'renameFilesFromTable_report') as z)
set #inserted_columncount = 0
set #loop_columns = 1
declare inserted_columnnames cursor scroll for -- these are not really the inserted ones, but we are going to test them 1 by 1
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'renameFilesFromTable_report'
set #params = '#is_there_in bit output'
open inserted_columnnames
fetch next from inserted_columnnames into #current_columnname
select * into #temp_for_dynamic_sql from inserted -- this is necessary because the scope of sp_executesql does not include inserted pseudo table
while (#loop_columns <= #actual_num_of_columns) -- looping with independent integer arithmetic
begin
set #sql_test = '
set #is_there_in = 0
if exists (select ['+#current_columnname+'] from #temp_for_dynamic_sql where ['+#current_columnname+'] is not null)
set #is_there_in = 1'
exec sp_executesql #sql_test, #params, #is_there output
if #is_there = 1
begin
fetch next from inserted_columnnames into #current_columnname
set #inserted_columncount = #inserted_columncount + 1
set #loop_columns = #loop_columns + 1
end
else if #is_there <> 1
begin
fetch next from inserted_columnnames into #current_columnname
set #loop_columns = #loop_columns + 1
end
end
close inserted_columnnames
deallocate inserted_columnnames
-- at this point we hold in two int variables the number of columns participating in the insert and the total number of columns
]
Then you can simply do if #inserted_columncount < #actual_num_of_columns ..........
I did this because i have a sp that inserts 1 complete line to the report table every time it runs. That's fine, but i don't want anyone else touching that table by mistake. not even myself. I also want to keep history. So i made this trigger to keep the history but also to check if an insert was attempted without values for all the columns in the report table, and further down the code it checks if an update or delete was attempted and it rollbacks.
i was thinking of expanding this to allow an update but in which all the columns are set.
this could possibly be done as follows:
if update was attempted,
and exists (
select possibly_excluded.COLUMN_NAME from (
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'renameFilesFromTable_report') as possibly_excluded
group by possibly_excluded.COLUMN_NAME
having COLUMN_NAME not in (
select COLUMN_NAME
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = 'renameFilesFromTable_report' and
sys.fn_IsBitSetInBitmask(#ColumnsUpdated, COLUMNPROPERTY(OBJECT_ID(TABLE_SCHEMA + '.' + TABLE_NAME), COLUMN_NAME, 'ColumnID')) <> 0)
)
begin
rollback transaction
print 'Only updates that set the values for a complete row are allowed on the report table..'
end
I have a query that is dynamically fetching the stored proc names from all the databases.
Now I want to execute the stored procs and store the result in a temptable or table variable.
How to do that. Here is my SP so far
Declare #GetDBNames sysname
Declare #DynSql nvarchar(max)
Declare DBNames cursor for
Select '['+name+']' from master.dbo.sysdatabases
open DBNames
FETCH NEXT FROM DBNames into #GetDBNames
WHILE ##FETCH_STATUS=0
BEGIN
SET #DynSql = '
Select Specific_Catalog as Database_Name, Routine_Name as ''Stored Procedure Name''
From '+ #GetDBNames+'.Information_Schema.Routines '
EXEC (#DynSql)
FETCH NEXT FROM DBNames into #GetDBNames
END
Close DBNames
Deallocate DBNames
Please help.
Thanks in advance
Here's my soluton. Cursors are evil :)
Declare #DynSql nvarchar(max)
declare #result table ([Database_Name] nvarchar(128), [Stored Procedure Name] sysname)
SET #DynSql = ''
select #DynSql = #DynSql + '
Select SPECIFIC_CATALOG COLLATE DATABASE_DEFAULT as Database_Name, ROUTINE_NAME COLLATE DATABASE_DEFAULT as [Stored Procedure Name]
From ' + NAME + '.INFORMATION_SCHEMA.ROUTINES' + CHAR(13) + 'union all' + CHAR(13)
from master.dbo.sysdatabases
--remove last "union all"
SET #DynSql = left(#DynSql, LEN(#DynSql) - 10)
insert #result
exec sp_executesql #DynSql
select * from #result
INSERT [TableName] EXEC (#DynSql)
Note that if you introduce data you may want to use sp_ExecuteSQL, and you probably want to use [/] object-name escaping.