带有 pg-promise 的多行插入 [英] Multi-row insert with pg-promise
问题描述
我想用一个 INSERT 查询插入多行，例如:
I would like to insert multiple rows with a single INSERT query, for example:
INSERT INTO tmp(col_a,col_b) VALUES('a1','b1'),('a2','b2')...
有没有一种方法可以轻松做到这一点，最好是针对这样的对象数组:
Is there a way to do this easily, preferably for an array of objects like these:
[{col_a:'a1',col_b:'b1'},{col_a:'a2',col_b:'b2'}]
我可能会在一个块中得到 500 条记录，因此运行多个查询是不可取的.
I might end up with 500 records in one chunk, so running multiple queries would be undesirable.
到目前为止，我只能为单个对象执行此操作:
So far I have been able to do it for a single object only:
INSERT INTO tmp(col_a,col_b) VALUES(${col_a},${col_b})
作为一个附带问题:使用 ${} 符号的插入是否可以防止 SQL 注入?
As a side question: Are insertions using ${} notation protected against SQL injections?
推荐答案
我是 的作者pg-承诺.
在旧版本的库中，中的简化示例涵盖了这一点Performance Boost 文章，在编写高性能数据库应用程序时仍然值得一读.
In older versions of the library this was covered by simplified examples within the Performance Boost article, which is still a good read when writing high-performance database applications.
较新的方法是依赖 helpers 命名空间，它最终是灵活的，并针对性能进行了优化.
The newer approach is to rely on the helpers namespace, which is ultimately flexible, and optimised for performance.
const pgp = require('pg-promise')({
/* initialization options */
capSQL: true // capitalize all generated SQL
});
const db = pgp(/*connection*/);
// our set of columns, to be created only once (statically), and then reused,
// to let it cache up its formatting templates for high performance:
const cs = new pgp.helpers.ColumnSet(['col_a', 'col_b'], {table: 'tmp'});
// data input values:
const values = [{col_a: 'a1', col_b: 'b1'}, {col_a: 'a2', col_b: 'b2'}];
// generating a multi-row insert query:
const query = pgp.helpers.insert(values, cs);
//=> INSERT INTO "tmp"("col_a","col_b") VALUES('a1','b1'),('a2','b2')
// executing the query:
await db.none(query);
这种插入甚至不需要事务，因为如果一组值插入失败，则不会插入.
Such an insert doesn't even require a transaction, because if one set of values fails to insert, none will insert.
您可以使用相同的方法生成以下任何查询:
And you can use the same approach to generate any of the following queries:
- 单行
INSERT - 多行
INSERT - 单行
UPDATE - 多行
UPDATE
使用 ${} 符号的插入是否可以防止 sql 注入?
Are insertions using ${} notation protected against sql injection?
是的，但并不孤单.如果您要动态插入架构/表/列名称，请务必使用 SQL 名称，结合起来可以保护您的代码免受 SQL 注入.
Yes, but not alone. If you are inserting schema/table/column names dynamically, it is important to use SQL Names, which in combination will protect your code from SQL injection.
相关问题:PostgreSQL 在 Node.js 中的多行更新.js
问:如何同时获取每条新记录的id?
A: 只需将 RETURNING id 附加到您的查询中，然后使用 很多:
A: Simply by appending RETURNING id to your query, and executing it with method many:
const query = pgp.helpers.insert(values, cs) + ' RETURNING id';
const res = await db.many(query);
//=> [{id: 1}, {id: 2}, ...]
或者更好的是，获取 id-s，并将结果转换为整数数组，使用方法 地图:
or even better, get the id-s, and convert the result into array of integers, using method map:
const res = await db.map(query, undefined, a => +a.id);
//=> [1, 2, ...]
要了解我们为什么在那里使用 +，请参阅:pg-promise 以字符串形式返回整数.
To understand why we used + there, see: pg-promise returns integers as strings.
UPDATE-1
要插入大量记录，请参阅数据导入.
For inserting huge number of records, see Data Imports.
UPDATE-2
使用 v8.2.1 及更高版本，您可以将静态查询生成包装到一个函数中，因此它可以在查询方法中生成，以在查询生成失败时拒绝:
Using v8.2.1 and later, you can wrap the static query-generation into a function, so it can be generated within the query method, to reject when the query generation fails:
// generating a multi-row insert query inside a function:
const query = () => pgp.helpers.insert(values, cs);
//=> INSERT INTO "tmp"("col_a","col_b") VALUES('a1','b1'),('a2','b2')
// executing the query as a function that generates the query:
await db.none(query);
这篇关于带有 pg-promise 的多行插入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
