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Diffstat (limited to 'doc/src/sgml/sql.sgml')
| -rw-r--r-- | doc/src/sgml/sql.sgml | 47 |
1 files changed, 25 insertions, 22 deletions
diff --git a/doc/src/sgml/sql.sgml b/doc/src/sgml/sql.sgml index 423f5155d24..9e788ff0616 100644 --- a/doc/src/sgml/sql.sgml +++ b/doc/src/sgml/sql.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.28 2003/01/15 18:01:05 momjian Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.29 2003/02/19 04:06:28 momjian Exp $ --> <chapter id="sql"> @@ -24,7 +24,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.28 2003/01/15 18:01:05 momjian <para> <acronym>SQL</acronym> has become the most popular relational query language. - The name "<acronym>SQL</acronym>" is an abbreviation for + The name <quote><acronym>SQL</acronym></quote> is an abbreviation for <firstterm>Structured Query Language</firstterm>. In 1974 Donald Chamberlin and others defined the language SEQUEL (<firstterm>Structured English Query @@ -72,10 +72,10 @@ $Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.28 2003/01/15 18:01:05 momjian (<acronym>ISO</acronym>). This original standard version of <acronym>SQL</acronym> is often referred to, - informally, as "<abbrev>SQL/86</abbrev>". In 1989 the original + informally, as <quote><abbrev>SQL/86</abbrev></quote>. In 1989 the original standard was extended and this new standard is often, again informally, referred to as - "<abbrev>SQL/89</abbrev>". Also in 1989, a related standard called + <quote><abbrev>SQL/89</abbrev></quote>. Also in 1989, a related standard called <firstterm>Database Language Embedded <acronym>SQL</acronym></firstterm> (<acronym>ESQL</acronym>) was developed. </para> @@ -86,11 +86,11 @@ $Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.28 2003/01/15 18:01:05 momjian definition of a greatly expanded version of the original standard, referred to informally as <firstterm><acronym>SQL2</acronym></firstterm> or <firstterm><acronym>SQL/92</acronym></firstterm>. This version became a - ratified standard - "International Standard ISO/IEC 9075:1992, - Database Language <acronym>SQL</acronym>" - in late 1992. + ratified standard - <quote>International Standard ISO/IEC 9075:1992, + Database Language <acronym>SQL</acronym></quote> - in late 1992. <acronym>SQL/92</acronym> is the version - normally meant when people refer to "the <acronym>SQL</acronym> - standard". A detailed + normally meant when people refer to <quote>the <acronym>SQL</acronym> + standard</quote>. A detailed description of <acronym>SQL/92</acronym> is given in <xref linkend="DATE97" endterm="DATE97">. At the time of writing this document a new standard informally referred to @@ -768,8 +768,8 @@ x(A) ∣ F(x) can be formulated using relational algebra can also be formulated using the relational calculus and vice versa. This was first proved by E. F. Codd in - 1972. This proof is based on an algorithm ("Codd's reduction - algorithm") by which an arbitrary expression of the relational + 1972. This proof is based on an algorithm (<quote>Codd's reduction + algorithm</quote>) by which an arbitrary expression of the relational calculus can be reduced to a semantically equivalent expression of relational algebra. For a more detailed discussion on that refer to <xref linkend="DATE94" endterm="DATE94"> @@ -778,11 +778,12 @@ x(A) ∣ F(x) </para> <para> - It is sometimes said that languages based on the relational calculus - are "higher level" or "more declarative" than languages based on - relational algebra because the algebra (partially) specifies the order - of operations while the calculus leaves it to a compiler or - interpreter to determine the most efficient order of evaluation. + It is sometimes said that languages based on the relational + calculus are <quote>higher level</quote> or <quote>more + declarative</quote> than languages based on relational algebra + because the algebra (partially) specifies the order of operations + while the calculus leaves it to a compiler or interpreter to + determine the most efficient order of evaluation. </para> </sect2> </sect1> @@ -870,9 +871,10 @@ SELECT [ ALL | DISTINCT [ ON ( <replaceable class="PARAMETER">expression</replac </para> <para> - Now we will illustrate the complex syntax of the SELECT statement - with various examples. The tables used for the examples are defined in - <xref linkend="supplier-fig" endterm="supplier-fig">. + Now we will illustrate the complex syntax of the + <command>SELECT</command> statement with various examples. The + tables used for the examples are defined in <xref + linkend="supplier-fig" endterm="supplier-fig">. </para> <sect3> @@ -903,7 +905,7 @@ SELECT * FROM PART </para> <para> - Using "*" in the SELECT statement will deliver all attributes from + Using <quote>*</quote> in the SELECT statement will deliver all attributes from the table. If we want to retrieve only the attributes PNAME and PRICE from table PART we use the statement: @@ -922,9 +924,10 @@ SELECT PNAME, PRICE Cam | 25 </programlisting> - Note that the <acronym>SQL</acronym> SELECT corresponds to the - "projection" in relational algebra not to the "selection" - (see <xref linkend="rel-alg" endterm="rel-alg"> for more details). + Note that the <acronym>SQL</acronym> SELECT corresponds to the + <quote>projection</quote> in relational algebra not to the + <quote>selection</quote> (see <xref linkend="rel-alg" + endterm="rel-alg"> for more details). </para> <para> |