In 1982 the American National Standards Institute (ANSI ) approved a rudimentary version of the Structured Query Language (SQL ) produced by IBM to query the database in a relational database management system (RDBMS ). Since then the SQL language becomes the standard for querying databases universally adopted by all manufacturers.
Over the years, SQL has undergone several revivals by the Committee of ANSI SQL, the last of which dates back to 1996.
It was therefore an attempt at unity that would allow all databases speak the same language. In reality, however, every kind of language presents substantial differences that have enabled this project to fulfill their potential.
Given the age and the consequent evolution of this language, we have defined different levels of standards over time. The most important are SQL89, SQL92 and SQL99 , also known as SQL1, SQL2 and SQL3 respectively. The adhesion of the various systems to the standard SQL92 DBMS is never complete and perfect, so have been defined in this sub-standard to define the degree of compatibility of a DBMS. They are: entry SQL, SQL intermediate and full SQL . It may mean that the former is the minimum level of compatibility and the last represents the total compatibility. The de facto standard is represented mainly by the first level, which basically coincides with the former standard, SQL89. From this we understand that the state of assimilation of SQL99 is even more backward.
Over the years, SQL has undergone several revivals by the Committee of ANSI SQL, the last of which dates back to 1996.
It was therefore an attempt at unity that would allow all databases speak the same language. In reality, however, every kind of language presents substantial differences that have enabled this project to fulfill their potential.
Given the age and the consequent evolution of this language, we have defined different levels of standards over time. The most important are SQL89, SQL92 and SQL99 , also known as SQL1, SQL2 and SQL3 respectively. The adhesion of the various systems to the standard SQL92 DBMS is never complete and perfect, so have been defined in this sub-standard to define the degree of compatibility of a DBMS. They are: entry SQL, SQL intermediate and full SQL . It may mean that the former is the minimum level of compatibility and the last represents the total compatibility. The de facto standard is represented mainly by the first level, which basically coincides with the former standard, SQL89. From this we understand that the state of assimilation of SQL99 is even more backward.
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