Delete from database - sql

Question

I want to delete a specific attribute from each and every table in the database. For an example: I want to delete CustomerID (column name) with a value of '2' from each and every table in the database
I am trying to delete records where there is a customer field and it has a value of 2 but I get an error that says there is incorrect syntax near keyword delete
declare #SearchTerm nvarchar(4000)
declare #ColumnName sysname
set #SearchTerm = N'2' -- Term to be searched for
set #ColumnName = N'customerID' --**column**
set nocount on
declare #TabCols table (
id int not null primary key identity
, table_schema sysname not null
, table_name sysname not null
, column_name sysname not null
, data_type sysname not null
)
insert into #TabCols (table_schema, table_name, column_name, data_type)
select
t.TABLE_SCHEMA, c.TABLE_NAME, c.COLUMN_NAME, c.DATA_TYPE
from INFORMATION_SCHEMA.TABLES t
join INFORMATION_SCHEMA.COLUMNS c on t.TABLE_SCHEMA = c.TABLE_SCHEMA
and t.TABLE_NAME = c.TABLE_NAME
where 1 = 1
and t.TABLE_TYPE = 'base table'
and c.DATA_TYPE not in ('image', 'sql_variant')
and c.COLUMN_NAME like case when len(#ColumnName) > 0 then #ColumnName else '%' end
order by c.TABLE_NAME, c.ORDINAL_POSITION
declare
#table_schema sysname
, #table_name sysname
, #column_name sysname
, #data_type sysname
, #exists nvarchar(4000) -- Can be max for SQL2005+
, #sql nvarchar(4000) -- Can be max for SQL2005+
, #where nvarchar(4000) -- Can be max for SQL2005+
, #run nvarchar(4000) -- Can be max for SQL2005+
while exists (select null from #TabCols) begin
select top 1
#table_schema = table_schema
, #table_name = table_name
-- , #exists = 'select null from [' + table_schema + '].[' + table_name + '] where 1 = 0'
, #sql = 'delete''' + '[' + table_schema + '].[' + table_name + ']' + ''' as TABLE_NAME, from [' + table_schema + '].[' + table_name + '] where 1 = 0'
, #where = ''
from #TabCols
order by id
while exists (select null from #TabCols where table_schema = #table_schema and table_name = #table_name) begin
select top 1
#column_name = column_name
, #data_type = data_type
from #TabCols
where table_schema = #table_schema
and table_name = #table_name
order by id
-- Special case for money
if #data_type in ('money', 'smallmoney') begin
if isnumeric(#SearchTerm) = 1 begin
set #where = #where + ' or [' + #column_name + '] = cast(''' + #SearchTerm + ''' as ' + #data_type + ')' -- could also cast the column as varchar for wildcards
end
end
-- Special case for xml
else if #data_type = 'xml' begin
set #where = #where + ' or cast([' + #column_name + '] as nvarchar(max)) like ''' + #SearchTerm + ''''
end
-- Special case for date
else if #data_type in ('date', 'datetime', 'datetime2', 'datetimeoffset', 'smalldatetime', 'time') begin
set #where = #where + ' or convert(nvarchar(50), [' + #column_name + '], 121) like ''' + #SearchTerm + ''''
end
-- Search all other types
else begin
set #where = #where + ' or [' + #column_name + '] like ''' + #SearchTerm + ''''
end
delete from #TabCols where table_schema = #table_schema and table_name = #table_name and column_name = #column_name
end
set #run = 'if exists(' + #exists + #where + ') begin ' + #sql + #where + ' print ''' + #table_name + ''' end'
print #run
exec sp_executesql #run
end
set nocount off

Answer 1

Here is another method based on the example posted by ewahner. The big difference is this doesn't use a cursor because you really don't need one for this.
declare #columnName nvarchar(255)
declare #intValue int
set #columnName = 'CustomerId'
set #intValue = 1
declare #DeleteValue varchar(10)
set #DeleteValue = convert(varchar(10), #intValue)
declare #sql nvarchar(max) = ''
select #sql = #sql + 'delete ' + object_name(c.object_id) + ' where ' + #columnName + ' = ' + #DeleteValue + ';'
from sys.columns c
where c.name = #columnName
select #sql
/* Uncomment the line below in order to run */
--exec sp_executesql #sql

Answer 2

Use at your own risk. You will need to uncomment the exec line. But first run it without uncommenting to make sure it gets the tables you want.
declare #columnName nvarchar(255)
declare #intValue int
set #columnName = 'CustomerId'
set #intValue = 1
declare curs cursor for
select object_name(c.object_id) as tableName
from sys.columns c
where c.name = #columnName
declare #tableName nvarchar(255)
open curs
fetch next from curs into #tableName
while ##fetch_status = 0
begin
declare #sql nvarchar(1000)
set #sql = 'delete ' + #tableName + ' where ' + #columnName + '=' + convert(varchar(10), #intValue)
print #sql
/* Uncomment the line below in order to run */
--exec sp_executesql #sql
fetch next from curs into #tableName
end
close curs
deallocate curs