MERGE 语句的语法错误

Question

我正在尝试在 Go 中执行 MERGE 语句：

query := "MERGE staged ON (email=$1)" +
" WHEN NOT MATCHED THEN INSERT (email, secret, passwd, ts, newAcct)" +
" VALUES($1,$2,$3,$4,TRUE)" +
" WHEN MATCHED THEN UPDATE staged SET" +
" newAcct=TRUE, existingUser=NULL, secret=$2, ts=$4"

_, err := db.Exec(query, email, secret, passwd, time.Now())

但我收到了这个错误：

pq: S:"ERROR" F:"scan.l" R:"scanner_yyerror" L:"1001" M:"syntax error at or near \"MERGE\"" P:"1" C:"42601"

同样的情况发生在 MySQL 中：

Error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'MERGE staged ON (email=?) WHEN NOT MATCHED THEN INSERT (email, secret, passwd, t' at line 1

怎么了？

Answer 1

MySQL 不支持MERGE，等效于

INSERT ... ON DUPLICATE KEY UPDATE

试试这个，

INSERT INTO tableName (email, secret, passwd, ts, newAcct) 
VALUES ($1,$2,$3,$4,TRUE)
ON DUPLICATE KEY UPDATE newAcct=TRUE, existingUser=NULL, secret=$2, ts=$4

但请确保将email 设置为Primary Key 或Unique。