插入示例

使用游标删除 包含一个 DELETE 语句的示例，其目的在于查找并删除表的重复的行。执行此任务的更好方式是选择期望的行，而不是删除不期望的行。下列 GBase 8s ESQL/C 示例中的代码展示执行此任务的一种方法：

EXEC SQL BEGIN DECLARE SECTION;
          long last_ord = 1;
          struct {
          long int o_num;
          date     o_date;
          long     c_num;
          char     o_shipinst[40];
          char     o_backlog;
          char     o_po[10];
          date     o_shipdate;
          decimal  o_shipwt;
          decimal  o_shipchg;
          date     o_paiddate;
          } ord_row;
          EXEC SQL END DECLARE SECTION;
          
          EXEC SQL BEGIN WORK;
          EXEC SQL INSERT INTO new_orders
          SELECT * FROM orders main
          WHERE 1 = (SELECT COUNT(*) FROM orders minor
          WHERE main.order_num = minor.order_num);
          EXEC SQL COMMIT WORK;
          
          EXEC SQL DECLARE dup_row CURSOR FOR
          SELECT * FROM orders main INTO :ord_row
          WHERE 1 < (SELECT COUNT(*) FROM orders minor
          WHERE main.order_num = minor.order_num)
          ORDER BY order_date;
          EXEC SQL DECLARE ins_row CURSOR FOR
          INSERT INTO new_orders VALUES (:ord_row);
          
          EXEC SQL BEGIN WORK;
          EXEC SQL OPEN ins_row;
          EXEC SQL OPEN dup_row;
          while(SQLCODE == 0)
          {
          EXEC SQL FETCH dup_row;
          if(SQLCODE == 0)
          {
          if(ord_row.o_num != last_ord)
          EXEC SQL PUT ins_row;
          last_ord = ord_row.o_num
          continue;
          }
          break;
          }
          if(SQLCODE != 0 && SQLCODE != 100)
          EXEC SQL ROLLBACK WORK;
          else
          EXEC SQL COMMIT WORK;
          EXEC SQL CLOSE ins_row;
          EXEC SQL CLOSE dup_row;