The simplest way to retrieve a scalar result is via the MySqlCommand.ExecuteScalar method:
public object ScalarQueryResult( string sql ) {
object obj = null;
MySqlCommand cmd = new MySqlCommand();
try {
cmd.CommandText = sql;
cmd.Connection = Connector.Connection;
obj = cmd.ExecuteScalar();
}
catch ( MySqlException ex ) {
this.ErrMsg( ex );
}
finally {
cmd.Dispose();
}
return obj;
}
object, which must then be cast into a type that's suitable for the retrieved value. Thus for a method to retrieve a rowcount under a Where clause, write ...
public Int64 TableRows( string schema, string table, string where ) {
string sql = "SELECT COUNT(*) FROM " + schema + "." + table + " " + where;
return Int64.Parse( ScalarQueryResult( sql ).ToString() );
}
public string ColumnType(
string schema, string table,
string column ) {
string sql =
"SELECT data_type FROM " + information_schema.columns " +
"WHERE table_schema='" + schema + "'" + "AND " +
"table_name='" + table + "' AND column_name='" + column + "'";
return ScalarQueryResult( sql ).ToString();
}
Last updated 22 May 2024 |