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SQL-92 was the third revision of the SQL database query language. Unlike SQL-89, it was a major revision of the standard. Aside from a few minor incompatibilities, the SQL-89 standard is forward-compatible with SQL-92. The standard specification itself grew about five times compared to SQL-89.
The time may be left out, but there is no way to define a variable that only contains the time. There is no DATETIME type. And there is a TIME type. But there is no TIMESTAMP type that can contain fine-grained timestamp up to millisecond or nanosecond. The TO_DATE function can be used to convert strings to date values. The function converts the ...
TIMESTAMP: This is a DATE and a TIME put together in one variable (e.g. 2011-05-03 15:51:36.123456). TIMESTAMP WITH TIME ZONE: the same as TIMESTAMP, but including details about the time zone in question. The SQL function EXTRACT can be used for extracting
Many computer systems measure time and date using Unix time, an international standard for digital timekeeping. Unix time is defined as the number of seconds elapsed since 00:00:00 UTC on 1 January 1970 (an arbitrarily chosen time based on the creation of the first Unix system), which has been dubbed the Unix epoch. [6]
A distinction is sometimes made between the terms datestamp, timestamp and date-timestamp: Datestamp or DS : A date, for example 2025-02-10 according to ISO 8601 Timestamp or TS : A time of day, for example 17:02:36 using 24-hour clock
Note (9): Despite the lack of a date datatype, SQLite does include date and time functions, [83] which work for timestamps between 24 November 4714 B.C. and 1 November 5352. Note (10): Informix DATETIME type has adjustable range from YEAR only through 1/10000th second.
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
Reserved words in SQL and related products In SQL:2023 [3] In IBM Db2 13 [4] In Mimer SQL 11.0 [5] In MySQL 8.0 [6] In Oracle Database 23c [7] In PostgreSQL 16 [1] In Microsoft SQL Server 2022 [2]