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Get the schema of the result returned by the selected query

Is it possible to get the schema of the result returned by SELECT Query? Below is the code:

string SQLQuery = "SELECT DISTINCT c.name 'Column Name',  t.Name 'Data type' FROM" +
                   " sys.columns c INNER JOIN " +
                   " sys.types t ON c.system_type_id = t.system_type_id" +
                   " LEFT OUTER JOIN " +
                   " sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id" +
                   " LEFT OUTER JOIN" +
                   " sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id" +
                   " WHERE" +
                   " c.object_id = OBJECT_ID('[DB].[dbo].[" + ddlTable.SelectedItem.Text + "]') AND t.name <> 'sysname'";

This code returns the column names along with the data type for the specified table. My requirement is to get the column names along with the data type from the select query, and not directly indicate the table name. as

  string SQLQuery = "SELECT DISTINCT c.name 'Column Name',  t.Name 'Data type' FROM" +
                       " sys.columns c INNER JOIN " +
                       " sys.types t ON c.system_type_id = t.system_type_id" +
                       " LEFT OUTER JOIN " +
                       " sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id" +
                       " LEFT OUTER JOIN" +
                       " sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id" +
                       " WHERE" +
                       " c.object_id = OBJECT_ID('SELECT col1, col2 from table(s)') AND t.name <> 'sysname'";

Although this does not work.

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2 answers

You can SELECT the query result to a temporary table, and metadata from this table. If you choose this solution, you need to make sure that the temporary table name is UNIQUE for each call, otherwise the metadata in the information_schema views will be shared in sessions.

if OBJECT_ID('tempdb..#tmp') is not null drop table #tmp

select * 
into #tmp
from Customer where 1 = 0 
-- select with a false predicate in order to ONLY get
--     metadata of the query and no rows of data.

select * from #tmp
-- Then select metadata from information_schema view
select COLUMN_NAME, DATA_TYPE from tempdb.information_schema.columns where TABLE_NAME like '#tmp%'

Result:
CustomerId  int
CustomerType    int
Name    nvarchar
IsActive    bit

, , #, , , . :

static void Main(string[] args)
        {
            string connStr = "Data Source=localhost;Initial Catalog=AdventureWorks;Integrated Security=True";
            SqlCommand cmd = new SqlCommand("select * from Orders where 1 = 0", new SqlConnection(connStr));

            SqlDataAdapter ad = new SqlDataAdapter(cmd);

            DataSet ds = new DataSet();
            ad.FillSchema(ds, SchemaType.Mapped);
            var metaTable = ds.Tables[0];

            foreach (DataColumn col in metaTable.Columns)
            {
                Console.WriteLine("{0} : {1}", col.DataType, col.ColumnName);
            }

         }

:

System.Int32 : OrderId
System.Int32 : CustomerId
System.Int32 : ArticleId
System.Decimal : TotalAmount
System.DateTime : OrderDate
+1

, SQL 2008, , 2012 sp_describe_first_result_set, .

. docs

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