MYSQL 动态sql语句

动态sql语句 格式1

直接执行sql声明(sqlstatement)
例程：
stringMysql
Mysql = "CREATE TABLE Employee "&
+"(emp_id integer not null,"&
+"dept_id integer not null, "&
+"emp_fname char(10) not null, "&
+"emp_lname char(20) not null)"
EXECUTE IMMEDIATE :Mysql ;

动态sql语句 格式2

准备sql声明(sqlsa)
执行sql声明(sqlsa)
例程：
INTEmp_id_var = 56
PREPARE SQLSA
FROM "DELETE FROM employee WHERE emp_id=?" ;
EXECUTE SQLSA USING :Emp_id_var ;

动态sql语句 格式3

为动态传输区 声明 游标|进程动态游标|进程
根据sql声明(sqlca)准备动态传输区
打开动态游标
取出游标进程值
关闭游标
例程：
integer Emp_id_var

DECLARE my_cursor DYNAMIC CURSOR FOR SQLSA ;
PREPARE SQLSA FROM "SELECT emp_id FROM employee" ;
OPEN DYNAMIC my_cursor ;
FETCH my_cursor INTO :Emp_id_var ;
CLOSE my_cursor ;

动态sql 格式4

为动态传输区 声明 游标|进程动态游标|进程
根据sql声明(sqlca)准备动态传输区
写入动态描述区
打开动态游标
取出游标进程值
关闭游标
例程：

string Stringvar, Sqlstatement
integer Intvar
Sqlstatement = "SELECT emp_id FROM employee"
PREPARE SQLSA FROM :Sqlstatement ;
DESCRIBE SQLSA INTO SQLDA ;
DECLARE my_cursor DYNAMIC CURSOR FOR SQLSA ;
OPEN DYNAMIC my_cursor USING DESCRIPTOR SQLDA ;
FETCH my_cursor USING DESCRIPTOR SQLDA ;

// If the FETCH is successful, the output
// descriptor array will contain returned
// values from the first row of the result set.
// SQLDA.NumOutputs contains the number of
// output descriptors.
// The SQLDA.OutParmType array will contain
// NumOutput entries and each entry will contain
// an value of the enumerated data type ParmType
// (such as TypeInteger!, or TypeString!).

CHOOSE CASE SQLDA.OutParmType[1]
CASE TypeString!
Stringvar = GetDynamicString(SQLDA, 1)
CASE TypeInteger!
Intvar = GetDynamicNumber(SQLDA, 1)

END CHOOSE
CLOSE my_cursor ;