![]() ![]() After you update it, this value becomes the time of change in the record. When you insert a record, the value of the timestamp field is the default current time. Moddatetime plug-in applies to all PostgreSQL versions, as long as it is available. The results of the above example are as follows: db1=# create extension moddatetime ĭb1(# moddate timestamp DEFAULT CURRENT_TIMESTAMP NOT NULLĭb1-# EXECUTE PROCEDURE moddatetime (moddate) ĭb1=# INSERT INTO mdt VALUES (1, 'first') ĭb1=# INSERT INTO mdt VALUES (2, 'second') ĭb1=# INSERT INTO mdt VALUES (3, 'third') Moddate timestamp DEFAULT CURRENT_TIMESTAMP NOT NULL ![]() Here is an example of moddatetime: DROP TABLE mdt The type of this column should be timestamp or timestamp with the time zone. You should define a single trigger argument: the name of the column to be altered. Tracking the last modified time of a specific row in a table is straightforward using this plug-in.Ĭreating a BEFORE UPDATE trigger using this function allows you to utilize it. ![]() You can use the moddatetime() plug-in to save the current time into a timestamp field. moddatetime - Functions for Tracking Last Modification Time This plug-in also tracks and alters the modified value.į.36.4. The default value of the timestamp field is the current time when you use the moddatetime plug-in. PG supports this function in two methods:Ģ) Virtual columns Method 1: Trigger-Track Timestamp by moddatetime This is enough to help the recovery process determine the relative order of page modifications, but the timestamp value has nothing to do with the time. Each time a page is modified, it is marked with the current value, and then this value is increased by one. The timestamp data type was initially introduced to support the SQL Server recovery algorithm. It is a binary number that indicates the relative order of data modifications that occurred in the database. There is an example in data type of SQL Server timestamp is independent of time and date. The column must be of type timestamp, or timestamp with the time zone. Then, specify a single trigger argument: the name of the column to be modified. To use it, create a BEFORE UPDATE trigger using this function. This can be useful for tracking the last modification time of a particular row within a table. Moddatetime - Functions for Tracking Last Modification Timemoddatetime() is a trigger that stores the current time into a timestamp field. Jan Wieck who told me about the timestamp_in("now") function.į.36.4. This is 95%+ based on autoinc.c, which I used as a starting point as I do It is a function to be called from a trigger for the purpose of updatingĪ modification datetime stamp in a record when that record is UPDATEd. Moddate timestamp DEFAULT CURRENT_TIMESTAMP NOT NULLĮXECUTE PROCEDURE moddatetime (moddate) - 自动将moddate字段更新为最新时间 With moddatetime, PostgreSQL's built-in tracking trigger function, the corresponding code can be found in the contrib directory of the code.
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