DECLARE @TableName sysname = NULL 
 
SELECT DB_NAME()        as [Database Name],  
        s.name            as [Schema Name], 
        t.name            as [Table Name], 
        c.name            as [Column Name], 
        ty.name            as [Column Data Type], 
        uty.name        as [Column System Type], 
        c.max_length    as [Column Maximum Length], 
        c.precision        as [Column Precision], 
        c.scale            as [Column Scale], 
        CASE c.is_nullable 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as [Column Is Nullable], 
        CASE c.is_identity 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as [Column Has Identity], 
        CASE c.is_computed 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as [Column Is Computed], 
        cc.definition    as [Computed Column Definition] 
FROM sys.tables as t 
INNER JOIN sys.schemas as s 
ON t.schema_id = s.schema_id 
INNER JOIN sys.columns as c 
ON t.object_id = c.object_id 
INNER JOIN sys.types as ty 
ON ty.user_type_id = c.user_type_id  
INNER JOIN sys.types as uty 
ON ty.system_type_id = uty.user_type_id 
LEFT JOIN sys.computed_columns as cc 
ON t.object_id = cc.object_id AND cc.column_id = c.column_id 
WHERE t.name = @TableName OR @TableName IS NULL 
UNION ALL 
SELECT DB_NAME()        as DatabaseName,  
        s.name            as SchemaName, 
        t.name            as TableName, 
        c.name            as ColumnName, 
        ty.name            as ColumnDataType, 
        ty.name            as ColumnSystemTypeName, 
        c.max_length    as ColumnMaximumLength, 
        c.precision        as ColumnPrecision, 
        c.scale            as ColumnScale, 
        CASE c.is_nullable 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as ColumnIsNullable, 
        CASE c.is_identity 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as ColumnHasIdentity, 
        CASE c.is_computed 
            WHEN 1 THEN 'Yes' 
            WHEN 0 THEN 'No' 
        END                as ColumnIsComputed, 
        cc.definition    as [Computed Column Definition] 
FROM sys.tables as t 
INNER JOIN sys.schemas as s 
ON t.schema_id = s.schema_id 
INNER JOIN sys.columns as c 
ON t.object_id = c.object_id 
INNER JOIN sys.types as ty 
ON ty.user_type_id = c.user_type_id AND ty.is_assembly_type = 1 
LEFT JOIN sys.computed_columns as cc 
ON t.object_id = cc.object_id AND cc.column_id = c.column_id 
WHERE t.name = @TableName OR @TableName IS NULL