Q:

How can I resolve my collation conflict in a better way?

I have a collation problem with my database and I have developed my own solution.
Solution:
DECLARE @new_collation varchar(128),
  @conflict_collation varchar(128),
  @cmd_holder varchar(2000),
  @cmd_complete varchar(2000),
  @schema varchar(128),
  @table_name varchar(128),
  @constraints_name varchar(128),
  @column_name varchar(128),
  @definition varchar(256),
  @data_type varchar(128),
  @type varchar(5),
  @length varchar(4),
  @nullability varchar(8),
  @db_name varchar(10)

SET @new_collation = 'SQL_Latin1_General_CP1_CI_AS'
SET @conflict_collation = 'French_CI_AS'

CREATE TABLE #LIST_CONSTRAINT(
  constraints_name VARCHAR(128),
  table_name VARCHAR(128),
  definition VARCHAR(256),
  type VARCHAR(10))

INSERT INTO #LIST_CONSTRAINT 
SELECT c.name AS constraints_name, o.name AS table_name, definition, 'CH' AS type
FROM sys.check_constraints c
INNER JOIN sysobjects o ON id = parent_object_id

INSERT INTO #LIST_CONSTRAINT 
SELECT i.name AS index_name, o.name AS table_name, c.name AS field_name, 'UQ' AS type
FROM sys.indexes i 
INNER JOIN sys.index_columns ic 
  ON i.object_id = ic.object_id and i.index_id = ic.index_id
INNER JOIN sys.columns c 
  ON ic.object_id = c.object_id and ic.column_id = c.column_id
INNER JOIN sys.objects o 
  ON i.object_id = o.object_id
WHERE is_unique_constraint = 1

SET @cmd_holder = 'ALTER TABLE $table_name DROP CONSTRAINT $constraints_name'

DECLARE column_cursor 
CURSOR FOR SELECT constraints_name, table_name FROM  #LIST_CONSTRAINT GROUP BY constraints_name, table_name
OPEN column_cursor
FETCH NEXT FROM column_cursor INTO @constraints_name, @table_name

WHILE @@Fetch_Status = 0
  BEGIN
    SELECT  @cmd_complete = @cmd_holder,
            @cmd_complete = Replace(@cmd_complete, '$table_name', '[' + @table_name +']'),
            @cmd_complete = Replace(@cmd_complete, '$constraints_name', @constraints_name)

    --PRINT @cmd_complete
    EXEC(@cmd_complete)
    FETCH NEXT FROM column_cursor INTO @constraints_name, @table_name
  END
CLOSE column_cursor
DEALLOCATE column_cursor

SELECT @db_name = DB_NAME()
EXEC('ALTER DATABASE ' + @db_name + ' COLLATE ' + @new_collation)  

SET @cmd_holder = 'ALTER TABLE $schema.$table_name ALTER COLUMN $column_name $data_type($length) COLLATE $new_collation $nullability'

DECLARE column_cursor CURSOR
  FOR SELECT  table_schema,
              table_name,
              column_name,
              data_type,
              CASE WHEN character_maximum_length = -1 THEN 'max'
                   ELSE Convert(varchar(4), character_maximum_length)
              END As length,
              CASE WHEN is_nullable = 'YES' THEN 'NULL'
                   ELSE 'NOT NULL'
              END As nullability
      FROM    information_schema.columns
      INNER JOIN sysobjects ON name = table_name
      WHERE  collation_name = @conflict_collation AND xtype = 'U'
       AND table_name NOT IN ('dtproperties', 'Exotics', 'ContractAccountsBalance', 'TechnicalParameters', 'SavingProducts', 'GeneralParameters')
OPEN column_cursor

FETCH NEXT FROM column_cursor INTO @schema, @table_name, @column_name, @data_type, @length, @nullability

WHILE @@Fetch_Status = 0
  BEGIN
    SELECT  @cmd_complete = @cmd_holder,
            @cmd_complete = Replace(@cmd_complete, '$schema', @schema),
            @cmd_complete = Replace(@cmd_complete, '$table_name', '[' + @table_name +']'),
            @cmd_complete = Replace(@cmd_complete, '$column_name', '[' + @column_name +']'),
            @cmd_complete = Replace(@cmd_complete, '$data_type', @data_type),
            @cmd_complete = Replace(@cmd_complete, '$length', @length),
            @cmd_complete = Replace(@cmd_complete, '$new_collation', @new_collation),
            @cmd_complete = Replace(@cmd_complete, '$nullability', @nullability),
            @cmd_complete = Replace(@cmd_complete, 'text(*)', 'text')

    --PRINT @cmd_complete
    EXEC(@cmd_complete)

    FETCH NEXT FROM column_cursor INTO @schema, @table_name, @column_name, @data_type, @length, @nullability
  END
CLOSE column_cursor
DEALLOCATE column_cursor

DECLARE @name_constraints VARCHAR(128)

DECLARE column_cursor 
CURSOR FOR SELECT constraints_name, table_name, definition, [type] FROM  #LIST_CONSTRAINT
OPEN column_cursor
FETCH NEXT FROM column_cursor INTO @constraints_name, @table_name, @definition, @type

WHILE @@Fetch_Status = 0
  BEGIN
    IF @type = 'CH'
    SET @cmd_holder = 'ALTER TABLE $table_name WITH NOCHECK ADD CONSTRAINT $constraints_name CHECK NOT FOR REPLICATION $definition ALTER TABLE $table_name CHECK CONSTRAINT $constraints_name'

    IF @type = 'UQ'
    BEGIN
      SET @cmd_holder = 'ALTER TABLE $table_name ADD CONSTRAINT $constraints_name UNIQUE NONCLUSTERED ($definition) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)'

      SET @definition = '';

      SELECT @definition = @definition + definition + ', '
      FROM #LIST_CONSTRAINT
      WHERE constraints_name = @constraints_name

      SELECT @definition = SUBSTRING(@definition, 1, LEN(@definition) - 1)         
    END

    SELECT  @cmd_complete = @cmd_holder,
            @cmd_complete = Replace(@cmd_complete, '$table_name', '[' + @table_name +']'),
            @cmd_complete = Replace(@cmd_complete, '$constraints_name', @constraints_name),
            @cmd_complete = Replace(@cmd_complete, '$definition', @definition)

    --PRINT @cmd_complete
    IF (@name_constraints <> @constraints_name)
      EXEC(@cmd_complete)

    SET @name_constraints = @constraints_name

    FETCH NEXT FROM column_cursor INTO @constraints_name, @table_name, @definition, @type
  END
CLOSE column_cursor
DEALLOCATE column_cursor

DROP TABLE #LIST_CONSTRAINT

Does anybody have another solution?
Can anybody offer some advice to optimize my code?

A:

I've seen this where the tempdb has a different default colation than your database, and I needed to add "COLLATE DATABASE_DEFAULT" to my comparisons e.g.
Create table #tmp
(
      mailbox varchar(50) not null
)
 . . .
Select t.mailbox, count(*)
from #tmp t inner join processed_email e
on t.mailbox = e.mailbox

becomes
Select t.mailbox, count(*)
from #tmp t inner join processed_email e
on t.mailbox COLLATE DATABASE_DEFAULT = e.mailbox COLLATE DATABASE_DEFAULT

