Database
Database class executes a SQL query to database engine directly.
Database.execNonQuery(sqlcmd)
Executes a SQL query without a return value.
Database.execScalar(sqlcmd)
Executes a SQL query with a single return value.
Database.execCommand(sqlcmd)
Executes a SQL query and returns a Field class with multiple return values. The number of the lines returned with this function is always one, and even if a result is two or more lines, the 2nd line or later is omitted. If you want to get the data after the 2nd line, please use FIRST-SKIP syntax(ex:SELECT FIRST 1 SKIP 2 * FROM MYTABLE;).