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diff --git a/doc/man/sql.l b/doc/man/sql.l deleted file mode 100644 index d6ad3eb6363..00000000000 --- a/doc/man/sql.l +++ /dev/null @@ -1,349 +0,0 @@ -.\" This is -*-nroff-*- -.\" XXX standard disclaimer belongs here.... -.\" $Header: /cvsroot/pgsql/doc/man/Attic/sql.l,v 1.1.1.1 1996/08/18 22:14:28 scrappy Exp $ -.TH INTRODUCTION SQL 11/5/95 Postgres95 Postgres95 -.SH "Section 4 \(em SQL Commands (COMMANDS)" -.SH "General Information" -.SH DESCRIPTION -The following is a description of the general syntax of SQL. -Individual SQL statements and commands are treated separately in the -document; this section describes the syntactic classes from which the -constituent parts of SQL statements are drawn. -.SH Comments -A -.IR comment -is an arbitrary sequence of characters following double dashes up to the end -of the line e.g: -.nf --- This is a comment -.fi -.SH "Names" -.IR Names -in SQL are sequences of not more than NAMEDATALEN alphanumeric characters, -starting with an alphabetic character. By default, NAMEDATALEN is set -to 16, but at the time the system is built, NAMEDATALEN can be changed -by changing the #ifdef in src/backend/include/postgres.h. Underscore -(\*(lq_\*(rq) is considered an alphabetic character. -.SH "Keywords" -The following identifiers are reserved for use as -.IR keywords -and may not be used otherwise: -.PP -.ft B -.nf -.if n .ta 5 +15 +15 +15 -.if t .ta 0.5i +1.5i +1.5i +1.5i -.fi -.ft -.ft B -.nf -.if n .ta 5 +15 +15 +15 -.if t .ta 0.5i +1.5i +1.5i +1.5i -.fi -.ft -.PP -In addition, all Postgres classes have several predefined attributes used -by the system. -.SH "Constants" -There are six types of -.IR constants -for use in SQL. They are described below. -.SH "String Constants" -.IR Strings -in SQL are arbitrary sequences of ASCII characters bounded by single -quotes (' '). Uppercase alphabetics within strings are accepted -literally. Non-printing characters may be embedded within strings by -prepending them with a backslash, e.g., `\en'. Also, in order to embed -quotes within strings, it is necessary to prefix them with `\e' . The -same convention applies to `\e' itself. Because of the limitations on -instance sizes, string constants are currently limited to a length of -a little less than 8192 bytes. Larger objects may be created using the -Postgres Large Object interface. -.SH "Integer Constants" -.IR "Integer constants" -in SQL are collection of ASCII digits with no decimal point. Legal -values range from \(mi2147483647 to +2147483647. This will vary -depending on the operating system and host machine. -.SH "Floating Point Constants" -.IR "Floating point constants" -consist of an integer part, a decimal point, and a fraction part or -scientific notation of the following format: -.nf -{<dig>} .{<dig>} [e [+-] {<dig>}] -.fi -Where <dig> is a digit. You must include at least one <dig> after the -period and after the [+-] if you use those options. An exponent with -a missing mantissa has a mantissa of 1 inserted. There may be no -extra characters embedded in the string. -Floating point constaints are of type float4. -.SH "Constants of Postgres User-Defined Types" -A constant of an -.IR arbitrary -type can be entered using the notation: -.nf -'string'::type-name -.fi -or -.nf -CAST 'string' AS type-name -.fi -The value inside the string is passed to the input -conversion routine for the type called type-name. The result is a -constant of the indicated type. The explicit typecast may be omitted -if there is no ambiguity as to the type the constant must be, in which -case it is automatically coerced. -.SH "Array constants" -.IR "Array constants" -are arrays of any Postgres type, including other arrays, string -constants, etc. The general format of an array constant is the -following: -.nf -{<val1><delim><val2><delim>} -.fi -Where -.IR "<delim>" -is the delimiter for the type stored in the \*(lqpg_type\*(rq class. -(For built-in types, this is the comma character, \*(lq,\*(rq.) An -example of an array constant is -.nf -{{1,2,3},{4,5,6},{7,8,9}} -.fi -This constant is a two-dimensional, 3 by 3 array consisting of three -sub-arrays of integers. -.PP -Individual array elements can and should be placed between quotation -marks whenever possible to avoid ambiguity problems with respect to -leading white space. -.\" Elements of single-element arrays (e.g., -.\" \*(lq{"1"}\*(rq) must be quoted. -.PP -.SH "FIELDS AND COLUMNS" -.SH "Fields" -A -.IR field -is either an attribute of a given class or one of the following: -.nf -oid -tmin -tmax -xmin -xmax -cmin -cmax -.fi -.PP -.IR Oid -stands for the unique identifier of an instance which is added by -Postgres to all instances automatically. Oids are not reused and are 32 -bit quantities. -.PP -.IR "Tmin, tmax, xmin, cmin, xmax" -and -.IR cmax -stand respectively for the time that the instance was inserted, the -time the instance was deleted, the identity of the inserting -transaction, the command identifier within the transaction, the -identity of the deleting transaction and its associated deleting -command. For further information on these fields consult [STON87]. -Times are represented internally as instances of the \*(lqabstime\*(rq -data type. Transaction identifiers are 32 bit quantities which are -assigned sequentially starting at 512. Command identifiers are 16 bit -objects; hence, it is an error to have more than 65535 SQL commands -within one transaction. -.SH "Columns" -A -.IR column -is a construct of the form: -.nf -Instance-variable{.composite_field}.field `['number`]' -.fi -.IR Instance-variable -identifies a particular class and can be thought of as standing for -the instances of that class. An instance variable is either a class -name, a surrogate for a class defined by means of a -.IR from -clause, or the keyword -.BR new -or -.BR current. -New and current can only appear in the action portion of a rule, while -other instance variables can be used in any SQL statement. -.IR Composite_field -is a field of of one of the Postgres composite types indicated in the -.IR information (l) -section, while successive composite fields address attributes in the -class(s) to which the composite field evaluates. Lastly, -.IR field -is a normal (base type) field in the class(s) last addressed. If -.IR field -is of type array, then the optional -.IR number -designator indicates a specific element in the array. If no number is -indicated, then all array elements are returned. -.SH "Operators" -Any built-in system, or user-defined operator may be used in SQL. -For the list of built-in and system operators consult -.BR "introduction" "(3)." -For a list of user-defined operators consult your system administrator -or run a query on the pg_operator class. Parentheses may be used for -arbitrary grouping of operators. -.SH "Expressions (a_expr)" -An -.IR expression -is one of the following: -.nf -( a_expr ) -constant -attribute -a_expr binary_operator a_expr -a_expr right_unary_operator -left_unary_operator a_expr -parameter -functional expressions -aggregate expressions -.fi -We have already discussed constants and attributes. The two kinds of -operator expressions indicate respectively binary and left_unary -expressions. The following sections discuss the remaining options. -.SH "Parameters" -A -.IR parameter -is used to indicate a parameter in a SQL function. Typically this -is used in SQL function definition statement. The form of a -parameter is: -.nf -\'$' number -.fi -For example, consider the definition of a function, DEPT, as -.nf -create function DEPT (char16) - returns dept - as 'select * from - dept where name=$1' - language 'sql' -.fi -.SH "Functional Expressions" -A -.IR "functional expression" -is the name of a legal SQL function, followed by its argument list -enclosed in parentheses, e.g.: -.nf -fn-name (a_expr{ , a_expr}) -.fi -For example, the following computes the square root of an employee -salary. -.nf -sqrt(emp.salary) -.fi -.SH "Aggregate Expression" -An -.IR "aggregate expression" -represents a simple aggregate (i.e., one that computes a single value) -or an aggregate function (i.e., one that computes a set of values). -The syntax is the following: -.nf -aggregate.name (attribute) -.fi -Here, -.IR aggregate_name -must be a previously defined aggregate. -.SH "Target_list" -A -.IR "target list" -is a parenthesized, comma-separated list of one or more elements, each -of which must be of the form: -.nf -a_expr[AS result_attname] -.fi -Here, result_attname is the name of the attribute to be created (or an -already existing attribute name in the case of update statements.) If -.IR result_attname -is not present, then -.IR a_expr -must contain only one attribute name which is assumed to be the name -of the result field. In Postgres default naming is only used if -.IR a_expr -is an attribute. -.SH‚‚ "Qualification" -A -.IR qualification -consists of any number of clauses connected by the logical operators: -.nf -not -and -or -.fi -A clause is an -.IR a_expr -that evaluates to a Boolean over a set of instances. -.SH "From List" -The -.IR "from list" -is a comma-separated list of -.IR "from expressions" . -.PP -Each -.IR "from expression" -is of the form: -.nf -[class_reference] instance_variable - {, [class_ref] instance_variable...} -.fi -where -.IR class_reference -is of the form -.nf -class_name [time_expression] [*] -.fi -The -.IR "from expression" -defines one or more instance variables to range over the class -indicated in -.IR class_reference . -Adding a -.IR time_expression -will indicate that a historical class is desired. One can also request -the instance variable to range over all classes that are beneath the -indicated class in the inheritance hierarchy by postpending the -designator \*(lq*\*(rq. -.SH‚‚ "Time Expressions" -A -.IR "time expression" -is in one of two forms: -.nf - ['date'] - ['date-1', 'date-2'] -.fi -The first case requires instances that are valid at the indicated -time. The second case requires instances that are valid at some time -within the date range specified. If no time expression is indicated, -the default is \*(lqnow\*(rq. -.PP -In each case, the date is a character string of the form -.nf -[MON-FRI] 'MMM DD [HH:MM:SS] YYYY' [Timezone] -.fi -where MMM is the month (Jan \- Dec), DD is a legal day number in the -specified month, HH:MM:SS is an optional time in that day (24-hour -clock), and YYYY is the year. If the time of day HH:MM:SS is not -specified, it defaults to midnight at the start of the specified day. -As of Version 3.0, times are no longer read and written using -Greenwich Mean Time; the input and output routines default to the -local time zone. -.PP -For example, -.nf -['Jan 1 1990'] -['Mar 3 00:00:00 1980', 'Mar 3 23:59:59 1981r'] -.fi -are valid time specifications. -.PP -Note that this syntax is slightly different than that used by the -time-range type. -.SH "SEE ALSO" -insert(l), -delete(l), -execute(l), -update(l), -select(l), -monitor(1). |