/// <summary>
/// Executes a T-SQL SELECT statement in format only mode (SET FMTONLY ON) which validates the query and returns the result metadata.
/// </summary>
/// <param name="query">The query builder instance.</param>
/// <param name="schema">Outputs the query metadata.</param>
/// <param name="errors">Outputs any validation or execution errors encountered.</param>
/// <returns></returns>
public static bool GetSchemaTable(this IDbQueryBuilder query, out DataTable schema, out ICollection <Exception> errors)
{
var cmd = query.CreateCommand();
errors = null;
schema = null;
try
{
using (var reader = cmd.ExecuteReader(CommandBehavior.SchemaOnly))
{
if (reader.FieldCount <= 0)
{
return(false);
}
schema = reader.GetSchemaTable();
}
return(true);
}
catch (Exception ex)
{
errors = new List <Exception>();
errors.Add(ex);
return(false);
}
}
/// <summary>
/// Executes a T-SQL SELECT statement in format only mode (SET FMTONLY ON) which validates the query and returns the result metadata.
/// </summary>
/// <param name="query"></param>
/// <param name="schema"></param>
/// <param name="errors"></param>
/// <returns></returns>
public static bool GetColumnSchema(this IDbQueryBuilder query, out ReadOnlyCollection <DbColumn> schema, out ICollection <Exception> errors)
{
var cmd = query.CreateCommand();
errors = null;
schema = null;
try
{
using (var reader = cmd.ExecuteReader(CommandBehavior.SchemaOnly))
{
if (reader.FieldCount <= 0)
{
return(false);
}
if (reader is System.Data.Common.IDbColumnSchemaGenerator)
{
schema = ((System.Data.Common.IDbColumnSchemaGenerator)reader).GetColumnSchema();
return(true);
}
else
{
throw new NotSupportedException("The interface System.Data.Common.IDbColumnSchemaGenerator is not supported by the underlying data provider.");
}
}
}
catch (Exception ex)
{
errors = new List <Exception>();
errors.Add(ex);
return(false);
}
}
/// <summary>
/// Executes the query and returns the first column from the first row in the result set.
/// </summary>
/// <param name="query">The query builder instance.</param>
/// <returns></returns>
public static object ExecuteScalar(this IDbQueryBuilder query)
{
return(query.CreateCommand().ExecuteScalar());
}
/// <summary>
/// Executes the query and returns an open data reader.
/// </summary>
/// <returns></returns>
public static IDataReader ExecuteReader(this IDbQueryBuilder query)
{
return(query.CreateCommand().ExecuteReader());
}
