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New data types defined: DATE, TIME, TIMESTAMP, INTERVAL, BIT string, VARCHAR strings, and NATIONAL CHARACTER strings. Support for additional character sets beyond the base requirement for representing SQL statements. New scalar operations such as string concatenation and substring extraction, date and time mathematics, and conditional statements.
The SQL function EXTRACT can be used for extracting a single field (seconds, for instance) of a datetime or interval value. The current system date / time of the database server can be called by using functions like CURRENT_DATE , CURRENT_TIMESTAMP , LOCALTIME , or LOCALTIMESTAMP .
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however.
DATE, TIME, TIMESTAMP (w/wo TIME ZONE) PERIOD, INTERVAL, GEOMETRY, XML, JSON, UDT (User Defined Type) UniData: Dynamic N/A N/A N/A N/A N/A N/A N/A N/A UniVerse: Dynamic N/A N/A N/A N/A N/A N/A N/A N/A Type system Integer Floating point Decimal String Binary Date/Time Boolean Other
A substantive difference between the TSQL2 proposal and what was adopted in SQL:2011 is that there are no hidden columns in the SQL:2011 treatment, nor does it have a new data type for intervals; instead two columns with datestamps (DS) or date-timestamps (DTS) can be bound together using a PERIOD FOR declaration. Another difference is ...
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 ...
These timestamps ensure that transactions affect each object in the same sequence of their respective timestamps. Thus, given two operations that affect the same object from different transactions, the operation of the transaction with the earlier timestamp must execute before the operation of the transaction with the later timestamp.
The period is an interval based on load times (called load datetime in data vault [1] [2]), also called inscription timestamp. [1] Other names of the interval is assertion timeline [3]), state timeline [3]) or technical timeline. [3] SQL:2011 has support for transaction time through so-called system-versioned tables. [4] [5] [6] [7]