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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 ...
PostgreSQL, MySQL and Oracle support natural joins; Microsoft T-SQL and IBM DB2 do not. The columns used in the join are implicit so the join code does not show which columns are expected, and a change in column names may change the results. In the SQL:2011 standard, natural joins are part of the optional F401, "Extended joined table", package.
E. F. Codd mentioned nulls as a method of representing missing data in the relational model in a 1975 paper in the FDT Bulletin of ACM-SIGMOD.Codd's paper that is most commonly cited with the semantics of Null (as adopted in SQL) is his 1979 paper in the ACM Transactions on Database Systems, in which he also introduced his Relational Model/Tasmania, although much of the other proposals from ...
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The crane crushed several vehicles and caused five deaths - two crane operators and three workers who were not properly harnessed. However, an inspection showed no structural damage to the building, and construction work was able to restart within a week. [17] Taipei 101's roof was completed three years later on 1 July 2003.
Stellantis N.V. is a multinational automotive manufacturing company formed from the merger in 2021 of the Italian–American conglomerate Fiat Chrysler Automobiles (FCA) and the French PSA Group.
Puerto Plata, officially known as San Felipe de Puerto Plata; (French: Port-de-Plate) [4] is a major coastal city in the Dominican Republic, and capital of the province of Puerto Plata. [5]
Operator(s) Tramways Department (1900-1948) Transport Department (1948-1964) [3] Track gauge: 4 ft (1,219 mm) Propulsion system(s) Electric Electrification: