sp_special_columns_90 (Transact-SQL MetaData) Definition

Please note: that the following source code is provided and copyrighted by Microsoft and is for educational purpose only.
The meta data is from an SQL 2012 Server.

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Definition:

sys.sp_special_columns_90(char @col_type
, char @scope
, char @nullable
, int @ODBCVer
, nvarchar @table_name
, nvarchar @table_owner
, nvarchar @table_qualifier)

MetaData:

   
create procedure sys.sp_special_columns_90  
(  
    @table_name         sysname,         --  Wildcard pattern matching IS NOT supported.  
    @table_owner        sysname = null,  --  Wildcard pattern matching IS NOT supported.  
    @table_qualifier    sysname = null,  
    @col_type           char(1) = 'R',  
    @scope              char(1) = 'T',   --  Not used in the search criteria.  
    @nullable           char(1) = 'U',  
    @ODBCVer            int = 2  
)  
as  
    declare @index_id           int  
    declare @table_id           int  
    --  quotename() returns up to 258 chars  
    declare @full_table_name    nvarchar(517) --  258 + 1 + 258  
    declare @scopeout           smallint  
  
    if @col_type not in ('R','V') or @col_type is null  
    begin  
        raiserror (15251,-1,-1,'col_type','''R'' or ''V''')  
        return  
    end  
  
    if @scope = 'C'  
        select @scopeout = 0  
    else if @scope = 'T'  
        select @scopeout = 1  
    else  
    begin  
        raiserror (15251,-1,-1,'scope','''C'' or ''T''')  
        return  
    end  
  
    if @nullable not in ('U','O') or @nullable is null  
    begin  
        raiserror (15251,-1,-1,'nullable','''U'' or ''O''')  
        return  
    end  
  
    if @table_qualifier is not null  
    begin  
        if db_name() <> @table_qualifier  
        begin --  If qualifier doesn't match current database  
            raiserror (15250, -1,-1)  
            return  
        end  
    end  
    if @table_owner is null  
    begin    --  If unqualified table name  
        select @full_table_name = quotename(@table_name)  
    end  
    else  
    begin   --  Qualified table name  
        if @table_owner = ''  
        begin   --  If empty owner name  
            select @full_table_name = quotename(@table_owner)  
        end  
        else  
        begin  
            select @full_table_name = quotename(@table_owner) + '.' + quotename(@table_name)  
        end  
    end  
  
    --   Get Object ID  
    select @table_id = object_id(@full_table_name)  
    if (@table_id is null) --  Return empty resultset if table doesn't exist  
    begin  
        select  
            SCOPE           = convert(smallint,0),  
            COLUMN_NAME     = convert(sysname,NULL),  
            DATA_TYPE       = convert(smallint,0),  
            TYPE_NAME       = convert(sysname,NULL),  
            "PRECISION"     = convert(int,0),  
            "LENGTH"        = convert(int,0),  
            SCALE           = convert(smallint,0),  
            PSEUDO_COLUMN   = convert(smallint,0)  
        where  
            1=0  
        return  
    end  
  
    if @col_type = 'V'  
    begin --  if ROWVER, just run that query  
        select  
            SCOPE           = convert(smallint,NULL),  
            COLUMN_NAME     = convert(sysname,c.name),  
            DATA_TYPE       = convert(smallint, -2),  
            TYPE_NAME       = t.name,  
            "PRECISION"     = convert(int,8),  
            "LENGTH"        = convert(int,8),  
            SCALE           = convert(smallint, NULL),  
            PSEUDO_COLUMN   = convert(smallint,1)  
        from  
            sys.types t,  
            sys.all_columns c  
        where  
            c.object_id = @table_id and  
            t.name = 'timestamp' and  
            t.user_type_id = c.system_type_id and  
            t.user_type_id = c.user_type_id  
        return  
    end  
  
    --  ROWID, now find the id of the 'best' index for this table  
  
    if @nullable = 'O'  --  Don't include any indexes that contain nullable columns.  
        select  
            @index_id = MIN(x.index_id)  
        from  
            sys.indexes x,  
            sys.all_columns c,  
            sys.all_columns c2  
        where  
            x.is_unique = 1 and --  If Unique Index  
            x.object_id = @table_id and  
            x.index_id > 0 and  --  Eliminate Table Row  
            c.object_id = x.object_id and  
            c2.object_id = c.object_id and  
            c.name = index_col(@table_name,x.index_id,c2.column_id)  
        group by  
            x.index_id HAVING SUM(convert (int, c.is_nullable)) = 0  
    else    --  Include indexes that are partially nullable.  
        select  
            @index_id = MIN(x.index_id)  
        from  
            sys.indexes x  
        where  
            x.is_unique = 1 and --  If Unique Index  
            x.object_id = @table_id and  
            x.index_id > 0      --  Eliminate Table Row  
  
    select  
        SCOPE           = @scopeout,  
        COLUMN_NAME     = convert(sysname,c.name),  
        DATA_TYPE       = convert(smallint,  
                                case  
                                when d.ss_dtype IN (40,41,42,43) then  --  DATE/TIME/DATETIME2/DATETIMEOFFSET  
                                    -9    
                                when (d.ss_dtype = 240 and c.max_length = -1) then --  Large UDT => varbinary(max) for 9.0 clients  
                                    -3  
                                else  
                                    d.DATA_TYPE  
                                end),  
        TYPE_NAME       = convert(sysname,case  
                                when (t.system_type_id = 240 or t.user_type_id > 255) then t.name  
                                else d.TYPE_NAME collate catalog_default  
                                end),  
        "PRECISION"     = convert(int,case  
                                when d.DATA_TYPE in (6,7) then d.data_precision         --  FLOAT/REAL  
                                when (c.max_length = -1 and d.ss_dtype = 240) then --  Large UDT => same precision as varbinary(max) for 9.0 clients  
                                    0  
                                else OdbcPrec(c.system_type_id,c.max_length,c.precision)  
                                end),  
        "LENGTH"        = convert(int,case  
                                when type_name(d.ss_dtype) IN ('numeric','decimal') then    --  decimal/numeric types  
                                    OdbcPrec(c.system_type_id,c.max_length,c.precision)+2  
                                when d.ss_dtype IN (40,41,42,43) then   
                                    OdbcPrec(c.system_type_id,c.max_length,c.precision)*2 --  DATE/TIME/DATETIME2/DATETIMEOFFSET  
                                when (c.max_length = -1 and d.ss_dtype = 240) then --  Large UDT => same length as varbinary(max) for 9.0 clients  
                                    0  
                                else  
                                    isnull(d.length, c.max_length)  
                                end),  
        SCALE           = convert(smallint,case  
                                when d.ss_dtype IN (40,41,42,43) then null  --  DATE/TIME/DATETIME2/DATETIMEOFFSET  
                                else OdbcScale(c.system_type_id,c.scale)  
                                end),  
        PSEUDO_COLUMN   = convert(smallint,1)  
    from  
        sys.columns c inner join  
        sys.indexes x on  
            (  
                x.object_id = c.object_id and  
                x.object_id = @table_id and  
                x.index_id = @index_id  
            ) inner join  
        sys.types t on  
            (  
                t.user_type_id = c.user_type_id  
            ) inner join  
        sys.spt_datatype_info d on  
            (  
                d.ss_dtype = c.system_type_id and  
                d.ODBCVer = @ODBCVer and  
                d.AUTO_INCREMENT = c.is_identity  
            ) inner join  
        sys.columns c2 on --  Self-join to generate list of index columns and to extract datatype names.  
            (  
                INDEX_COL(@full_table_name,@index_id,c2.column_id) = c.name and  
                c2.object_id = x.object_id  
            )