[英]How do I use parameters for the source in a MERGE statement in Informix?
我正在尝试对 Informix 数据库执行合并语句,如下所示:
MERGE INTO aa_rec AS dest
USING (SELECT '123456' AS id, '111-222-3333' as phone, '' as phone_ext, 'CELL' as aa FROM sysmaster:'informix'.sysdual) AS src
ON dest.id = src.id AND dest.aa = src.aa
WHEN NOT MATCHED THEN
INSERT (dest.id, dest.aa, dest.beg_date, dest.phone, dest.phone_ext, dest.ofc_add_by)
VALUES (src.id, src.aa, TODAY, src.phone, src.phone_ext, 'TEST')
WHEN MATCHED THEN UPDATE SET
dest.phone = src.phone,
dest.phone_ext = src.phone_ext,
dest.beg_date = '10/29/2019',
dest.ofc_add_by = 'TEST'
此语句按原样使用硬编码值,但我想为源表中的值传递参数:
USING (SELECT ? AS id, ? as phone, ? as phone_ext, 'CELL' as aa FROM sysmaster:'informix'.sysdual) AS src
当我使用参数和有效值执行语句时,我收到此错误:
E42000: (-201) 出现语法错误。
MERGE 语句的源代码部分是否支持参数? 如果是,我的语法错误在哪里?
对于上下文,我使用 Informix 的 OleDb 提供程序从 ASP.NET 调用它。
你有:
SELECT ? AS id, ? as phone, ? as phone_ext, 'CELL' as aa FROM sysmaster:'informix'.sysdual
您不能对 SELECT 语句的“结构”元素使用占位符( ?
符号)。 您不能在占位符中提供列名。 并且通过选择列表中的占位符将数字等作为值传递也不起作用。
我可能会创建一个适当形状的临时表,并在其中插入一行,然后在 select 语句中使用临时表:
SELECT '123456' AS id, '111-222-3333' AS phone, '' AS phone_ext, 'CELL' AS aa
FROM sysmaster:'informix'.sysdual
INTO TEMP phone_data;
MERGE INTO aa_rec AS dest
USING (SELECT * FROM phone_data) AS src
ON dest.id = src.id AND dest.aa = src.aa
WHEN NOT MATCHED THEN
INSERT (dest.id, dest.aa, dest.beg_date, dest.phone, dest.phone_ext, dest.ofc_add_by)
VALUES (src.id, src.aa, TODAY, src.phone, src.phone_ext, 'TEST')
WHEN MATCHED THEN UPDATE SET
dest.phone = src.phone,
dest.phone_ext = src.phone_ext,
dest.beg_date = '10/29/2019',
dest.ofc_add_by = 'TEST'
;
DROP TABLE phone_data;
显式创建临时表可能比使用 INTO TEMP 子句更好/更安全。 类型不一定是您所期望的(CHAR(6)、CHAR(12)、VARCHAR(1)、CHAR(4))——尽管这可能无关紧要。
显然,一旦临时表存在,您就可以使用任何可用的机制将任何适合的数据插入到临时表中:
INSERT INTO phone_data(id, phone, phone_ext, aa) VALUES(?, ?, ?, ?)
请记住,临时表是会话专用的——您可以让很多人同时使用相同的临时表名称,而不会相互干扰。
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