hi I am trying to search all the columns and tables in a data server that contain a specific date value e.g. '2021-07-22' in SQL server database.
Please notice is NOT a string type, but a datetime type.
I googled and did quite a bit research but could not find anything available. Can anyone provide some help please?
Thanks
DECLARE #SearchDate DATE = '2022-01-01'
DECLARE #SQL NVARCHAR(MAX) = ''
DECLARE #SchemaName SYSNAME
DECLARE #TableName SYSNAME
DECLARE #ColumnName SYSNAME
DECLARE #RowIDName SYSNAME
DECLARE #Results TABLE(ColumnName SYSNAME,RowIDName SYSNAME,RowIDValue NVARCHAR(255), ColumnValue DATETIME)
DECLARE #TableCols CURSOR
SET #TableCols = CURSOR FOR
SELECT QUOTENAME(s.name) AS SchemaName,QUOTENAME(t.name) AS TableName,QUOTENAME(c.name) AS ColumnName,QUOTENAME(Ids.ID) AS RowIDName
FROM sys.tables t
JOIN sys.columns c ON t.object_id = c.object_id
JOIN sys.schemas s ON s.schema_id = t.schema_id
CROSS APPLY (SELECT TYPE_NAME(c.system_type_id))TypeNames(TypeName)
CROSS APPLY (SELECT c2.Name FROM sys.Columns c2 WHERE c2.column_id = 1 AND c2.object_id = c.object_id)IDs(ID)
WHERE t.is_ms_shipped = 0
AND TypeNames.TypeName IN ('date','datetime','datetime2','smalldatetime')
OPEN #TableCols
FETCH NEXT FROM #TableCols INTO #SchemaName,#TableName, #ColumnName,#RowIDName
WHILE ##fetch_status = 0
BEGIN
INSERT INTO #Results(ColumnName,RowIDName,RowIDValue,ColumnValue)
EXEC
(
'SELECT ''' + #SchemaName+'.'+#TableName + '.' + #ColumnName + ''','''+#RowIDName+''','+#RowIDName+' ,' + #ColumnName + '
FROM ' + #TableName +
' WHERE ' + #ColumnName + ' = ''' + #SearchDate+''''
)
FETCH NEXT FROM #TableCols INTO #SchemaName,#TableName, #ColumnName,#RowIDName
END
CLOSE #TableCols
DEALLOCATE #TableCols
SELECT * FROM #Results
I have the following query, I want use a nested cursor in my query. How to do this, because it's not running and I am new to SQL Server. Please help me
CHECK TABLE SUGGEST LAT 31.8181 LONG 71.4146
Msg 16915, Level 16, State 1, Procedure Sp_CheckCarStatusMeter, Line
266
A cursor with the name 'ShapeCursor' already exists. ELSE OPEN
CURSOR
Msg 16905, Level 16, State 1, Procedure Sp_CheckCarStatusMeter,
Line 296
The cursor is already open.
Code:
DECLARE SuggestCursor CURSOR FOR
SELECT TOP 100
rtha.car_id, rtha.latitude, rtha.longitude
FROM
Carhistory rtha
WHERE
rtha.car_id = 6142 ;
OPEN SuggestCursor;
FETCH NEXT FROM SuggestCursor INTO #CarSuggested, #carlatprevious, #carlongprevious;
WHILE (##FETCH_STATUS = 0)
BEGIN
PRINT 'CHECK TABLE SUGGEST LAT '+#carlatprevious +' LONG '+ #carlongprevious;
DECLARE ShapeCursor CURSOR FOR
SELECT
g.ID, #carID, g.ShapeType
FROM
tblgeo AS g
WHERE
car_id #ID;
IF (SELECT CURSOR_STATUS('local','ShapeCursor')) >= -1
BEGIN
Print 'DEALLOCATE CURSOR'
--DEALLOCATE ShapeCursor
END
ELSE
Print 'ELSE OPEN CURSOR'
OPEN ShapeCursor;
FETCH NEXT FROM ShapeCursor INTO #ID, #CarIdx, #ShapeType;
WHILE (##FETCH_STATUS = 0)
BEGIN
Example with nested cursors:
DECLARE
#crTables CURSOR,
#crColumns CURSOR,
#table_id INT,
#table_name VARCHAR(100),
#column_id INT,
#column_name VARCHAR(100)
SET #crTables = CURSOR FAST_FORWARD FOR
SELECT TOP 10 [object_id], NAME
FROM sys.tables t
ORDER BY t.[object_id] DESC
OPEN #crTables
FETCH NEXT FROM #crTables
INTO #table_id, #table_name
WHILE ##FETCH_STATUS = 0
BEGIN
PRINT #table_name + ': '
SET #crColumns = CURSOR FAST_FORWARD FOR
SELECT TOP 10 c.column_id, c.name
FROM sys.[columns] c
WHERE c.[object_id] = #table_id
ORDER BY c.column_id
OPEN #crColumns
FETCH NEXT FROM #crColumns
INTO #column_id, #column_name
WHILE ##FETCH_STATUS = 0
BEGIN
PRINT #column_name
FETCH NEXT FROM #crColumns
INTO #column_id, #column_name
END
CLOSE #crColumns
DEALLOCATE #crColumns
PRINT ''
FETCH NEXT FROM #crTables
INTO #table_id, #table_name
END
CLOSE #crTables
DEALLOCATE #crTables
GO
Which will give the same result as:
GO
DECLARE #txt VARCHAR(MAX)
SET #txt =
STUFF(
(
SELECT TOP 10
CHAR(13) + CHAR(10) + NAME
+ (
SELECT TOP 10 CHAR(13) + CHAR(10) + c.name
FROM sys.[columns] c
WHERE c.[object_id] = t.[object_id]
ORDER BY c.column_id
FOR XML PATH(''), TYPE
).value('.', 'VARCHAR(MAX)')
+ CHAR(13) + CHAR(10)
FROM sys.tables t
ORDER BY t.[object_id] DESC
FOR XML PATH(''), TYPE
).value('.', 'VARCHAR(MAX)'), 1, 2, '')
PRINT #txt
Try to avoid cursors.
We have a vendor specific application that has 100's of tables and most of them have a column called Company_Code and within that column is stored a value for each company. Is it possible to search the entire database where COMPANY_CODE = 'TST' and return those values?
This should do the trick:
DECLARE #Value varchar(100) = 'TST';
DECLARE #script varchar(1000);
CREATE TABLE ##Results (TableName VARCHAR(100) , ValueCount INT);
DECLARE db_cursor CURSOR FOR
WITH cte AS
(
SELECT o.NAME AS TableName , c.name As ColumnName
FROM sys.sysobjects o
JOIN sys.syscolumns c on o.id = c.id
WHERE c.name = 'COMPANY_CODE '
)
SELECT 'INSERT INTO ##Results (TableName , ValueCount) SELECT ''' + TableName + ''' , COUNT(*) FROM ' + TableName + ' WHERE ' + ColumnName + ' = ''' + #Value + '''' AS Script
FROM cte;
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO #script
WHILE ##FETCH_STATUS = 0
BEGIN
PRINT #script;
EXEC (#Script);
FETCH NEXT FROM db_cursor INTO #script
END
CLOSE db_cursor
DEALLOCATE db_cursor
SELECT * FROM ##Results WHERE ValueCount > 0
I want to update some rows which be include some null fields.
How can I update these rows in SQL Server?
I am asking because a rows has got 180 fields. :)
Please help me.
You can use dynamic SQL to generate a script to run. The following will probably need tweaking for you to exclude columns that you don't want to update etc.
DECLARE #TableName nvarchar(500) = '[dbo].[T]'
DECLARE #DynSql nvarchar(max)
SELECT #DynSql = ISNULL(#DynSql+',','') + QUOTENAME(name) + '= ISNULL(' + QUOTENAME(name) + ',0)'
FROM sys.columns
WHERE object_id = OBJECT_ID(#TableName)
SET #DynSql = 'UPDATE ' + #TableName + 'SET ' + #DynSql
PRINT #DynSql
--EXEC(#DynSql)
I think I understand what you are asking. This will generate an update statement for each column in your table that will set it's value to 0 if it's value is null.
declare #tableName nvarchar(100)
declare #querys varchar(max)
set #querys = ''
set #tableName = 'YOUR TABLE NAME HERE'
select #querys = #querys + 'update ' + #tableName + ' set ' +
QUOTENAME(t.[name]) + '=0 where ' + QUOTENAME(t.[name]) + ' is null;'
from (SELECT [name] FROM syscolumns
WHERE id = (SELECT id
FROM sysobjects
WHERE type = 'U'
AND [NAME] = #tableName))t
select #querys
execute sp_executesql #sqlQuery
Well It is an old post, but I recently had this problem and wanted a dynamic SQL query using the above solution that performed the update depending on column types.
USE [YOUR DATABASE]
DECLARE #tableName nvarchar(100)
DECLARE #name varchar(50)
DECLARE #dtype varchar(50)
DECLARE #CMD NVARCHAR (200)
SET #tableName = [YOUR TABLE NAME]
DECLARE db_cursor CURSOR FOR
SELECT c.name, t.name AS Dtype
FROM sys.columns c
INNER JOIN sys.types t
ON t.system_type_id = c.system_type_id
WHERE c.[object_id] =
(SELECT [object_id] FROM sys.objects WHERE type = 'U' AND [NAME] = #tableName)
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO #name, #Dtype
WHILE ##FETCH_STATUS = 0 BEGIN
SET #CMD = 'UPDATE ' + #tableName + ' SET ' + quotename(#name) +' = ' +
(CASE
WHEN (#Dtype = 'bit') THEN '0'
WHEN (#Dtype = 'int') THEN '0'
WHEN (#Dtype = 'decimal') THEN '0'
WHEN (#Dtype = 'date') THEN '''1/1/1900'''
WHEN (#Dtype = 'datetime') THEN '''1/1/1900'''
WHEN (#Dtype = 'uniqueidentifier') THEN '00000000-0000-0000-0000-000000000000'
ELSE ''''''
END )
+ ' WHERE ' + quotename(#name) +' IS NULL'
PRINT #CMD
EXEC sp_executeSQL #cmd
FETCH NEXT FROM db_cursor INTO #name, #Dtype
END
CLOSE db_cursor
DEALLOCATE db_cursor
How do I select all the columns in a table that only contain NULL values for all the rows? I'm using MS SQL Server 2005. I'm trying to find out which columns are not used in the table so I can delete them.
Here is the sql 2005 or later version: Replace ADDR_Address with your tablename.
declare #col varchar(255), #cmd varchar(max)
DECLARE getinfo cursor for
SELECT c.name FROM sys.tables t JOIN sys.columns c ON t.Object_ID = c.Object_ID
WHERE t.Name = 'ADDR_Address'
OPEN getinfo
FETCH NEXT FROM getinfo into #col
WHILE ##FETCH_STATUS = 0
BEGIN
SELECT #cmd = 'IF NOT EXISTS (SELECT top 1 * FROM ADDR_Address WHERE [' + #col + '] IS NOT NULL) BEGIN print ''' + #col + ''' end'
EXEC(#cmd)
FETCH NEXT FROM getinfo into #col
END
CLOSE getinfo
DEALLOCATE getinfo
SELECT cols
FROM table
WHERE cols IS NULL
This should give you a list of all columns in the table "Person" that has only NULL-values. You will get the results as multiple result-sets, which are either empty or contains the name of a single column. You need to replace "Person" in two places to use it with another table.
DECLARE crs CURSOR LOCAL FAST_FORWARD FOR SELECT name FROM syscolumns WHERE id=OBJECT_ID('Person')
OPEN crs
DECLARE #name sysname
FETCH NEXT FROM crs INTO #name
WHILE ##FETCH_STATUS = 0
BEGIN
EXEC('SELECT ''' + #name + ''' WHERE NOT EXISTS (SELECT * FROM Person WHERE ' + #name + ' IS NOT NULL)')
FETCH NEXT FROM crs INTO #name
END
CLOSE crs
DEALLOCATE crs
Or did you want to just see if a column only has NULL values (and, thus, is probably unused)?
Further clarification of the question might help.
EDIT:
Ok.. here's some really rough code to get you going...
SET NOCOUNT ON
DECLARE #TableName Varchar(100)
SET #TableName='YourTableName'
CREATE TABLE #NullColumns (ColumnName Varchar(100), OnlyNulls BIT)
INSERT INTO #NullColumns (ColumnName, OnlyNulls) SELECT c.name, 0 FROM syscolumns c INNER JOIN sysobjects o ON c.id = o.id AND o.name = #TableName AND o.xtype = 'U'
DECLARE #DynamicSQL AS Nvarchar(2000)
DECLARE #ColumnName Varchar(100)
DECLARE #RC INT
SELECT TOP 1 #ColumnName = ColumnName FROM #NullColumns WHERE OnlyNulls=0
WHILE ##ROWCOUNT > 0
BEGIN
SET #RC=0
SET #DynamicSQL = 'SELECT TOP 1 1 As HasNonNulls FROM ' + #TableName + ' (nolock) WHERE ''' + #ColumnName + ''' IS NOT NULL'
EXEC sp_executesql #DynamicSQL
set #RC=##rowcount
IF #RC=1
BEGIN
SET #DynamicSQL = 'UPDATE #NullColumns SET OnlyNulls=1 WHERE ColumnName=''' + #ColumnName + ''''
EXEC sp_executesql #DynamicSQL
END
ELSE
BEGIN
SET #DynamicSQL = 'DELETE FROM #NullColumns WHERE ColumnName=''' + #ColumnName+ ''''
EXEC sp_executesql #DynamicSQL
END
SELECT TOP 1 #ColumnName = ColumnName FROM #NullColumns WHERE OnlyNulls=0
END
SELECT * FROM #NullColumns
DROP TABLE #NullColumns
SET NOCOUNT OFF
Yes, there are easier ways, but I have a meeting to go to right now. Good luck!
Here is an updated version of Bryan's query for 2008 and later. It uses INFORMATION_SCHEMA.COLUMNS, adds variables for the table schema and table name. The column data type was added to the output. Including the column data type helps when looking for a column of a particular data type. I didn't added the column widths or anything.
For output the RAISERROR ... WITH NOWAIT is used so text will display immediately instead of all at once (for the most part) at the end like PRINT does.
SET NOCOUNT ON;
DECLARE
#ColumnName sysname
,#DataType nvarchar(128)
,#cmd nvarchar(max)
,#TableSchema nvarchar(128) = 'dbo'
,#TableName sysname = 'TableName';
DECLARE getinfo CURSOR FOR
SELECT
c.COLUMN_NAME
,c.DATA_TYPE
FROM
INFORMATION_SCHEMA.COLUMNS AS c
WHERE
c.TABLE_SCHEMA = #TableSchema
AND c.TABLE_NAME = #TableName;
OPEN getinfo;
FETCH NEXT FROM getinfo INTO #ColumnName, #DataType;
WHILE ##FETCH_STATUS = 0
BEGIN
SET #cmd = N'IF NOT EXISTS (SELECT * FROM ' + #TableSchema + N'.' + #TableName + N' WHERE [' + #ColumnName + N'] IS NOT NULL) RAISERROR(''' + #ColumnName + N' (' + #DataType + N')'', 0, 0) WITH NOWAIT;';
EXECUTE (#cmd);
FETCH NEXT FROM getinfo INTO #ColumnName, #DataType;
END;
CLOSE getinfo;
DEALLOCATE getinfo;
You can do:
select
count(<columnName>)
from
<tableName>
If the count returns 0 that means that all rows in that column all NULL (or there is no rows at all in the table)
can be changed to
select
case(count(<columnName>)) when 0 then 'Nulls Only' else 'Some Values' end
from
<tableName>
If you want to automate it you can use system tables to iterate the column names in the table you are interested in
If you need to list all rows where all the column values are NULL, then i'd use the COLLATE function. This takes a list of values and returns the first non-null value. If you add all the column names to the list, then use IS NULL, you should get all the rows containing only nulls.
SELECT * FROM MyTable WHERE COLLATE(Col1, Col2, Col3, Col4......) IS NULL
You shouldn't really have any tables with ALL the columns null, as this means you don't have a primary key (not allowed to be null). Not having a primary key is something to be avoided; this breaks the first normal form.
Try this -
DECLARE #table VARCHAR(100) = 'dbo.table'
DECLARE #sql NVARCHAR(MAX) = ''
SELECT #sql = #sql + 'IF NOT EXISTS(SELECT 1 FROM ' + #table + ' WHERE ' + c.name + ' IS NOT NULL) PRINT ''' + c.name + ''''
FROM sys.objects o
JOIN sys.columns c ON o.[object_id] = c.[object_id]
WHERE o.[type] = 'U'
AND o.[object_id] = OBJECT_ID(#table)
AND c.is_nullable = 1
EXEC(#sql)
Not actually sure about 2005, but 2008 ate it:
USE [DATABASE_NAME] -- !
GO
DECLARE #SQL NVARCHAR(MAX)
DECLARE #TableName VARCHAR(255)
SET #TableName = 'TABLE_NAME' -- !
SELECT #SQL =
(
SELECT
CHAR(10)
+'DELETE FROM ['+t1.TABLE_CATALOG+'].['+t1.TABLE_SCHEMA+'].['+t1.TABLE_NAME+'] WHERE '
+(
SELECT
CASE t2.ORDINAL_POSITION
WHEN (SELECT MIN(t3.ORDINAL_POSITION) FROM INFORMATION_SCHEMA.COLUMNS t3 WHERE t3.TABLE_NAME=t2.TABLE_NAME) THEN ''
ELSE 'AND '
END
+'['+COLUMN_NAME+'] IS NULL' AS 'data()'
FROM INFORMATION_SCHEMA.COLUMNS t2 WHERE t2.TABLE_NAME=t1.TABLE_NAME FOR XML PATH('')
) AS 'data()'
FROM INFORMATION_SCHEMA.TABLES t1 WHERE t1.TABLE_NAME = #TableName FOR XML PATH('')
)
SELECT #SQL -- EXEC(#SQL)
Here I have created a script for any kind of SQL table. please copy this stored procedure and create this on your Environment and run this stored procedure with your Table.
exec [dbo].[SP_RemoveNullValues] 'Your_Table_Name'
stored procedure
GO
/****** Object: StoredProcedure [dbo].[SP_RemoveNullValues] Script Date: 09/09/2019 11:26:53 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- akila liyanaarachchi
Create procedure [dbo].[SP_RemoveNullValues](#PTableName Varchar(50) ) as
begin
DECLARE Cussor CURSOR FOR
SELECT COLUMN_NAME,TABLE_NAME,DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = #PTableName
OPEN Cussor;
Declare #ColumnName Varchar(50)
Declare #TableName Varchar(50)
Declare #DataType Varchar(50)
Declare #Flage int
FETCH NEXT FROM Cussor INTO #ColumnName,#TableName,#DataType
WHILE ##FETCH_STATUS = 0
BEGIN
set #Flage=0
If(#DataType in('bigint','numeric','bit','smallint','decimal','smallmoney','int','tinyint','money','float','real'))
begin
set #Flage=1
end
If(#DataType in('date','atetimeoffset','datetime2','smalldatetime','datetime','time'))
begin
set #Flage=2
end
If(#DataType in('char','varchar','text','nchar','nvarchar','ntext'))
begin
set #Flage=3
end
If(#DataType in('binary','varbinary'))
begin
set #Flage=4
end
DECLARE #SQL VARCHAR(MAX)
if (#Flage in(1,4))
begin
SET #SQL =' update ['+#TableName+'] set ['+#ColumnName+']=0 where ['+#ColumnName+'] is null'
end
if (#Flage =3)
begin
SET #SQL =' update ['+#TableName+'] set ['+#ColumnName+'] = '''' where ['+#ColumnName+'] is null '
end
if (#Flage =2)
begin
SET #SQL =' update ['+#TableName+'] set ['+#ColumnName+'] ='+'''1901-01-01 00:00:00.000'''+' where ['+#ColumnName+'] is null '
end
EXEC(#SQL)
FETCH NEXT FROM Cussor INTO #ColumnName,#TableName,#DataType
END
CLOSE Cussor
DEALLOCATE Cussor
END
You'll have to loop over the set of columns and check each one. You should be able to get a list of all columns with a DESCRIBE table command.
Pseudo-code:
foreach $column ($cols) {
query("SELECT count(*) FROM table WHERE $column IS NOT NULL")
if($result is zero) {
# $column contains only null values"
push #onlyNullColumns, $column;
} else {
# $column contains non-null values
}
}
return #onlyNullColumns;
I know this seems a little counterintuitive but SQL does not provide a native method of selecting columns, only rows.
I would also recommend to search for fields which all have the same value, not just NULL.
That is, for each column in each table do the query:
SELECT COUNT(DISTINCT field) FROM tableName
and concentrate on those which return 1 as a result.
SELECT t.column_name
FROM user_tab_columns t
WHERE t.nullable = 'Y' AND t.table_name = 'table name here' AND t.num_distinct = 0;
An updated version of 'user2466387' version, with an additional small test which can improve performance, because it's useless to test non nullable columns:
AND IS_NULLABLE = 'YES'
The full code:
SET NOCOUNT ON;
DECLARE
#ColumnName sysname
,#DataType nvarchar(128)
,#cmd nvarchar(max)
,#TableSchema nvarchar(128) = 'dbo'
,#TableName sysname = 'TableName';
DECLARE getinfo CURSOR FOR
SELECT
c.COLUMN_NAME
,c.DATA_TYPE
FROM
INFORMATION_SCHEMA.COLUMNS AS c
WHERE
c.TABLE_SCHEMA = #TableSchema
AND c.TABLE_NAME = #TableName
AND IS_NULLABLE = 'YES';
OPEN getinfo;
FETCH NEXT FROM getinfo INTO #ColumnName, #DataType;
WHILE ##FETCH_STATUS = 0
BEGIN
SET #cmd = N'IF NOT EXISTS (SELECT * FROM ' + #TableSchema + N'.' + #TableName + N' WHERE [' + #ColumnName + N'] IS NOT NULL) RAISERROR(''' + #ColumnName + N' (' + #DataType + N')'', 0, 0) WITH NOWAIT;';
EXECUTE (#cmd);
FETCH NEXT FROM getinfo INTO #ColumnName, #DataType;
END;
CLOSE getinfo;
DEALLOCATE getinfo;
You might need to clarify a bit. What are you really trying to accomplish? If you really want to find out the column names that only contain null values, then you will have to loop through the scheama and do a dynamic query based on that.
I don't know which DBMS you are using, so I'll put some pseudo-code here.
for each col
begin
#cmd = 'if not exists (select * from tablename where ' + col + ' is not null begin print ' + col + ' end'
exec(#cmd)
end