special Characters in DB query is failing - mysql

Question

I had created a db named as Suri's _DB and had below query is failing when executed. If the db name is given without single quote the query is executing successfully.
The query is
USE [master];
IF EXISTS (SELECT 1 FROM tempdb..sysobjects WHERE [Id] = OBJECT_ID('tempdb..#tmp_filegroups'))
BEGIN
DROP TABLE #tmp_filegroups
END
CREATE TABLE #tmp_filegroups
(
[DbName] nvarchar(128),
[DbId] int,
[GroupName] nvarchar(128),
[GroupId] int,
[IsFileStream] bit
)
IF EXISTS (SELECT 1 FROM tempdb..sysobjects WHERE [Id] = OBJECT_ID('tempdb..#tmp_dbandlogfiles'))
BEGIN
DROP TABLE #tmp_dbandlogfiles
END
CREATE TABLE #tmp_dbandlogfiles
(
[DbName] nvarchar(128),
[DbId] int,
[GroupId] int,
[Name] nvarchar(128),
[FileName] nvarchar(260),
[Size] float,
[IsReadOnlyMedia] bit,
[IsReadOnly] bit,
[IsOffline] bit,
[IsSparse] bit,
[IsPrimaryFile] bit,
[SpaceUsed] float,
[FileType] int
)
IF EXISTS (SELECT 1 FROM tempdb..sysobjects WHERE [Id] = OBJECT_ID('tempdb..#tmp_fulltextcatalogfiles'))
BEGIN
DROP TABLE #tmp_fulltextcatalogfiles
END
CREATE TABLE #tmp_fulltextcatalogfiles
(
[DbName] nvarchar(128),
[DbId] int,
[Name] nvarchar(128),
[Path] nvarchar(260)
)
DECLARE #DB NVARCHAR(128)
DECLARE #DBID int
DECLARE #CMD NVARCHAR(MAX)
DECLARE Databases CURSOR FAST_FORWARD FOR
SELECT name,dbid FROM master..sysdatabases
WHERE name in (N'Suri''s _DB')
OPEN Databases
FETCH NEXT FROM Databases INTO #DB, #DBID
WHILE (##FETCH_STATUS = 0)
BEGIN
BEGIN TRY
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''' + #DB + ''' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],s.name as [GroupName],s.data_space_id as [GroupId], CAST(case s.type when ''FD'' then 1 else 0 end AS bit) AS [IsFileStream] FROM sys.filegroups as s ORDER by [GroupId] ASC'
INSERT INTO #tmp_filegroups execute(#CMD)
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''' + #DB + ''' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],s.data_space_id as [GroupId],s.name AS [Name],s.physical_name AS [FileName],s.size * CONVERT(float,8) AS [Size],s.is_media_read_only AS [IsReadOnlyMedia],s.is_read_only AS [IsReadOnly],CAST(case s.state when 6 then 1 else 0 end AS bit) AS [IsOffline],s.is_sparse AS [IsSparse],CAST(CASE s.file_id WHEN 1 THEN 1 ELSE 0 END AS bit) AS [IsPrimaryFile],CAST(fileproperty(s.name,''SpaceUsed'') AS float) * CONVERT(float,8) AS [SpaceUsed], Type AS [FileType] FROM sys.database_files as s'
INSERT INTO #tmp_dbandlogfiles execute(#CMD)
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''' + #DB + ''' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],cat.name as [Name],cat.path as [Path] FROM sys.fulltext_catalogs AS cat ORDER by [Name] ASC'
INSERT INTO #tmp_fulltextcatalogfiles execute(#CMD)
END TRY
BEGIN CATCH
SELECT ERROR_MESSAGE() AS ERRMESS
END CATCH
FETCH NEXT FROM Databases INTO #DB, #DBID
END
CLOSE Databases
DEALLOCATE Databases
select [DbName],[DbId],[GroupName],[GroupId],[IsFileStream] from #tmp_filegroups
DROP TABLE #tmp_filegroups
Why this is failing?
I tried escaping the single quotes

Answer 1

When you build the sql query string, the dbname's single quote is not terminated. Replace any single quotes to 2 single quotes to terminate the character.
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''[' + replace(#DB, '''', '''''') + ']'' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],s.name as [GroupName],s.data_space_id as [GroupId], CAST(case s.type when ''FD'' then 1 else 0 end AS bit) AS [IsFileStream] FROM sys.filegroups as s ORDER by [GroupId] ASC'
INSERT INTO #tmp_filegroups execute(#CMD)
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''[' + replace(#DB, '''', '''''') + ']'' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],s.data_space_id as [GroupId],s.name AS [Name],s.physical_name AS [FileName],s.size * CONVERT(float,8) AS [Size],s.is_media_read_only AS [IsReadOnlyMedia],s.is_read_only AS [IsReadOnly],CAST(case s.state when 6 then 1 else 0 end AS bit) AS [IsOffline],s.is_sparse AS [IsSparse],CAST(CASE s.file_id WHEN 1 THEN 1 ELSE 0 END AS bit) AS [IsPrimaryFile],CAST(fileproperty(s.name,''SpaceUsed'') AS float) * CONVERT(float,8) AS [SpaceUsed], Type AS [FileType] FROM sys.database_files as s'
INSERT INTO #tmp_dbandlogfiles execute(#CMD)
SELECT #CMD = 'use ' + '[' + #DB + ']' + '; select N''[' + replace(#DB, '''', '''''') + ']'' as [DbName],' + CAST(#DBID as varchar(30)) + ' as [DbId],cat.name as [Name],cat.path as [Path] FROM sys.fulltext_catalogs AS cat ORDER by [Name] ASC'
INSERT INTO #tmp_fulltextcatalogfiles execute(#CMD)