TYPE — 定义新的数据类型
TYPEtype_name
ISctype
TYPE
命令定义一个新的 C 类型。它等同于将 typedef
放入声明部分。
只有在使用 -c
选项运行 ecpg
时,才会识别此命令。
EXEC SQL TYPE customer IS struct { varchar name[50]; int phone; }; EXEC SQL TYPE cust_ind IS struct ind { short name_ind; short phone_ind; }; EXEC SQL TYPE c IS char reference; EXEC SQL TYPE ind IS union { int integer; short smallint; }; EXEC SQL TYPE intarray IS int[AMOUNT]; EXEC SQL TYPE str IS varchar[BUFFERSIZ]; EXEC SQL TYPE string IS char[11];
这是一个使用 EXEC SQL TYPE
的示例程序
EXEC SQL WHENEVER SQLERROR SQLPRINT; EXEC SQL TYPE tt IS struct { varchar v[256]; int i; }; EXEC SQL TYPE tt_ind IS struct ind { short v_ind; short i_ind; }; int main(void) { EXEC SQL BEGIN DECLARE SECTION; tt t; tt_ind t_ind; EXEC SQL END DECLARE SECTION; EXEC SQL CONNECT TO testdb AS con1; EXEC SQL SELECT pg_catalog.set_config('search_path', '', false); EXEC SQL COMMIT; EXEC SQL SELECT current_database(), 256 INTO :t:t_ind LIMIT 1; printf("t.v = %s\n", t.v.arr); printf("t.i = %d\n", t.i); printf("t_ind.v_ind = %d\n", t_ind.v_ind); printf("t_ind.i_ind = %d\n", t_ind.i_ind); EXEC SQL DISCONNECT con1; return 0; }
此程序的输出如下所示
t.v = testdb t.i = 256 t_ind.v_ind = 0 t_ind.i_ind = 0
TYPE
命令是 PostgreSQL 扩展。