问题描述
我在项目中使用pg_connect和pg_query。
但是我真的不确定是否使用AutoCommit模式进行pg_connect吗？
I use pg_connect, and pg_query in a project.But I'm really not sure that is pg_connect using AutoCommit mode or not?
这是一个重要的问题，因为我需要在事务下编写一些块，如果服务器将忽略其中一个语句，则数据库将不一致...
It is important question, because I need to write some block under transaction, and if one of the statements would be ignored by the server, the database would be inconsistent...
还有一个有趣的问题，在执行后pg_query会提交吗？
Also interesting question that do pg_query a commit after execution?
例如：
pg_query('begin; update table1...; update table2...; commit');
与
pg_query('begin;');
pg_query('update table1...;');
pg_query('update table2...;');
pg_query('commit');
并且是
pg_query('begin; update table1...; update table2...; commit');
在自动提交模式下工作，那么开始和提交仍然有效吗？
working in AutoCommit mode, so begin and commit is nevertheless?
感谢您的帮助：
dd
Thanks for your help: dd
推荐答案
首先，PostgreSQL中没有AutoCommit模式和PHP API的pg_ *函数不会尝试模拟一个。
First, there is no AutoCommit mode in PostgreSQL and the pg_* functions of the PHP API do not try to emulate one.
pg_query的说
pg_query's doc says
pg_query（ UPDATE1 ..; UPDATE2 ...）在一个事务中执行，并且对数据产生全有或全无的影响。
So it guarantees that pg_query("UPDATE1 ..; UPDATE2...") executes in one transaction and has an all-or-nothing effect on the data.
序列
pg_query("BEGIN");
pg_query("UPDATE1...");
pg_query("UPDATE2..");
pg_query("COMMIT");
等效于 pg_query（ UPDATE1 ..; UPDATE2 ... ）关于数据完整性（半成品状态不会发生）。
is equivalent to pg_query("UPDATE1 ..; UPDATE2...") with regard to data integrity (half-finished state cannot happen).
关于注释除非有明确的BEGIN / COMMIT。 ..，仅当它们不在整个SQL语句链的开头和结尾时才有意义。
即 pg_query（ BEGIN; update1; update2; COMMIT;）; 等效于 pg_query（ update1; update2; ），但（显然）不等同于 pg_query（ update1; COMMIT; update2;）
As for the note "unless there are explicit BEGIN/COMMIT...", it is relevant only if these are not at the beginning and end of the entire chain of SQL statements.That is, pg_query("BEGIN; update1; update2; COMMIT;"); is equivalent to pg_query("update1; update2;") but (obviously) not equivalent to pg_query("update1; COMMIT; update2;")
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