使用ruby编写的INSERT语句示例pg gem

Question

做了大约半天的搜索，并且找不到使用pg gem（postgresql ruby​​ gem）准备好的INSERT语句的任何示例。

我想这（看着宝石文档后）：

def test2 
    conn = PG.connect(dbname: 'db1') 
    conn.prepare("statement1", 'INSERT INTO table1 (id, name, profile) VALUES (?, ?, ?)') 
end 

，但我得到了以下错误：

pgtest.rb:19:in `prepare': ERROR: syntax error at or near "," (PG::Error) 
LINE 1: INSERT INTO table1 (id, name, profile) VALUES (?, ?, ?) 
                 ^
from pgtest.rb:19:in `test2' 
from pgtest.rb:25:in `<main>' 

Answer 1

的pg宝石要你使用编号的占位符（$1，$2 ，...）而不是位置占位符（?）：

conn = PG.connect(:dbname => 'db1') 
conn.prepare('statement1', 'insert into table1 (id, name, profile) values ($1, $2, $3)') 
conn.exec_prepared('statement1', [ 11, 'J.R. "Bob" Dobbs', 'Too much is always better than not enough.' ]) 

的fine manual有这样一段话：

- (PGresult) prepare(stmt_name, sql[, param_types ])
[...]
PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.

为 exec_prepared

并再次：

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc.