public override void Visit(SqlUnion expression)
{
expression.Statements.For(
(index, statement) =>
{
if (index > 0)
{
_writer.WriteKeyword(SqlKeywords.Union);
}
_writer.WriteOpenParenthesis();
statement.Accept(this);
_writer.WriteCloseParenthesis();
});
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to an <see cref="IDbCommand"/>
/// instance for the specified <paramref name="connection" />.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlSelect"/> to convert to an <see cref="IDbCommand"/>.
/// </param>
/// <param name="connection">
/// The <see cref="IDbConnection"/> for which to create an <see cref="IDbCommand"/>.
/// </param>
/// <returns>
/// An <see cref="IDbCommand"/> for the specified <paramref name="connection"/> that reprents
/// the specified SQL expression tree.
/// </returns>
/// <remarks>
/// Any <see cref="SqlParameter"/> members of the <see cref="SqlSelect"/> expression are
/// automatically converted to <see cref="IDbDataParameter"/> instances and attached to
/// the returned <see cref="IDbCommand"/>.
/// </remarks>
public static IDbCommand ToCommand(this SqlUnion sql, IDbConnection connection)
{
return(connection.CreateCommandInternal(sql));
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to SQL text.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlUnion"/> to convert to SQL text.
/// </param>
/// <param name="dialect">
/// The <see cref="SqlDialect"/> used to format the SQL text.
/// </param>
/// <param name="parameterCallback">
/// A delegate that is called when a SQL parameter is encountered while converting the SQL expression.
/// </param>
/// <returns>
/// The SQL text for the specified SQL expression tree.
/// </returns>
public static string ToSql(this SqlUnion sql, SqlDialect dialect, Action <SqlParameter> parameterCallback)
{
return(sql.ToSqlInternal(dialect, parameterCallback));
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to SQL text.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlUnion"/> to convert to SQL text.
/// </param>
/// <param name="dialect">
/// The <see cref="SqlDialect"/> used to format the SQL text.
/// </param>
/// <returns>
/// The SQL text for the specified SQL expression tree.
/// </returns>
public static string ToSql(this SqlUnion sql, SqlDialect dialect)
{
return(sql.ToSqlInternal(dialect));
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to SQL text.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlUnion"/> to convert to SQL text.
/// </param>
/// <param name="parameterCallback">
/// A delegate that is called when a SQL parameter is encountered while converting the SQL expression.
/// </param>
/// <returns>
/// The SQL text for the specified SQL expression tree.
/// </returns>
public static string ToSql(this SqlUnion sql, Action <SqlParameter> parameterCallback)
{
return(sql.ToSql(null, parameterCallback));
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to SQL text.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlUnion"/> to convert to SQL text.
/// </param>
/// <returns>
/// The SQL text for the specified SQL expression tree.
/// </returns>
public static string ToSql(this SqlUnion sql)
{
return(sql.ToSql(null, null));
}
protected override SqlExpression VisitUnion(SqlUnion expression)
{
bool writeUnion = false;
foreach (SqlSelect statement in expression.Statements)
{
if (writeUnion)
{
_writer.WriteUnion();
}
_writer.WriteOpenParenthesis();
Visit(statement);
_writer.WriteCloseParenthesis();
writeUnion = true;
}
return expression;
}
/// <summary>
/// Converts the specified <see cref="SqlUnion"/> expression tree to an <see cref="IDbCommand"/>
/// instance for the specified <paramref name="connection" />.
/// </summary>
/// <param name="sql">
/// The <see cref="SqlUnion"/> to convert to an <see cref="IDbCommand"/>.
/// </param>
/// <param name="connection">
/// The <see cref="IDbConnection"/> for which to create an <see cref="IDbCommand"/>.
/// </param>
/// <returns>
/// An <see cref="IDbCommand"/> for the specified <paramref name="connection"/> that reprents
/// the specified SQL expression tree.
/// </returns>
/// <remarks>
/// Any <see cref="SqlParameter"/> members of the <see cref="SqlUnion"/> expression are
/// automatically converted to <see cref="IDbDataParameter"/> instances and attached to
/// the returned <see cref="IDbCommand"/>.
/// </remarks>
public static IDbCommand CreateCommand(this IDbConnection connection, SqlUnion sql)
{
return connection.CreateCommandInternal(sql);
}
