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Overview
Comment: | Update SQL syntax documentation to describe the new CAST expressions. (CVS 2531) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
d5392866bfd6e06c6d072f649356050b |
User & Date: | drh 2005-06-26 20:00:46.000 |
Context
2005-06-29
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15:33 | Make sqlite3Malloc always return NULL when the number of bytes to allocate is 0. (CVS 2532) (check-in: 657d74ebc1 user: drh tags: trunk) | |
2005-06-26
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20:00 | Update SQL syntax documentation to describe the new CAST expressions. (CVS 2531) (check-in: d5392866bf user: drh tags: trunk) | |
17:55 | Tcl interface uses Tcl_Objs to implement user-defined functions, thus allowing BLOB values to be transferred correctly. Ticket #1304. (CVS 2530) (check-in: 514aaab3f9 user: drh tags: trunk) | |
Changes
Changes to www/lang.tcl.
1 2 3 | # # Run this Tcl script to generate the lang-*.html files. # | | | 1 2 3 4 5 6 7 8 9 10 11 | # # Run this Tcl script to generate the lang-*.html files. # set rcsid {$Id: lang.tcl,v 1.93 2005/06/26 20:00:46 drh Exp $} source common.tcl if {[llength $argv]>0} { set outputdir [lindex $argv 0] } else { set outputdir "" } |
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911 912 913 914 915 916 917 | } Section expression expr Syntax {expr} { <expr> <binary-op> <expr> | | | < > | > | < < | 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 | } Section expression expr Syntax {expr} { <expr> <binary-op> <expr> | <expr> [NOT] <like-op> <expr> [ESCAPE <expr>] | <unary-op> <expr> | ( <expr> ) | <column-name> | <table-name> . <column-name> | <database-name> . <table-name> . <column-name> | <literal-value> | <parameter> | <function-name> ( <expr-list> | STAR ) | <expr> ISNULL | <expr> NOTNULL | <expr> [NOT] BETWEEN <expr> AND <expr> | <expr> [NOT] IN ( <value-list> ) | <expr> [NOT] IN ( <select-statement> ) | <expr> [NOT] IN [<database-name> .] <table-name> | [EXISTS] ( <select-statement> ) | CASE [<expr>] LP WHEN <expr> THEN <expr> RPPLUS [ELSE <expr>] END | CAST ( <expr> AS <type> ) } {like-op} { LIKE | GLOB | REGEXP } puts { <p>This section is different from the others. Most other sections of this document talks about a particular SQL command. This section does not talk about a standalone command but about "expressions" which are subcomponents of most other commands.</p> |
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960 961 962 963 964 965 966 | <p>Supported unary operators are these:</p> <blockquote><pre> <font color="#2c2cf0"><big>- + ! ~</big></font> </pre></blockquote> | < < < < < | | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 | <p>Supported unary operators are these:</p> <blockquote><pre> <font color="#2c2cf0"><big>- + ! ~</big></font> </pre></blockquote> <p>Note that there are two variations of the equals and not equals operators. Equals can be either} puts "[Operator =] or [Operator ==]. The non-equals operator can be either [Operator !=] or [Operator {<>}]. The [Operator ||] operator is \"concatenate\" - it joins together the two strings of its operands. The operator [Operator %] outputs the remainder of its left operand modulo its right operand.</p> <p>The result of any binary operator is a numeric value, except for the [Operator ||] concatenation operator which gives a string result.</p>" puts { <a name="literal_value"></a> <p> A literal value is an integer number or a floating point number. Scientific notation is supported. The "." character is always used as the decimal point even if the locale setting specifies "," for this role - the use of "," for the decimal point would result in syntactic ambiguity. A string constant is formed by enclosing the string in single quotes ('). A single quote within the string can be encoded by putting two single quotes in a row - as in Pascal. C-style escapes using the backslash character are not supported because they are not standard SQL. BLOB literals are string literals containing hexadecimal data and preceded by a single "x" or "X" character. For example:</p> <blockquote><pre> X'53514697465' </pre></blockquote> <p> A literal value can also be the token "NULL". </p> <p> A parameter specifies a placeholder in the expression for a literal value that is filled in at runtime using the <a href="capi3ref.html#sqlite3_bind_int">sqlite3_bind</a> API. Parameters can take several forms: </p <blockquote> <table> <tr> <td align="right" valign="top"><b>?</b><i>NNN</i></td><td width="20"></td> <td>A question mark followed by a number <i>NNN</i> holds a spot for the NNN-th parameter. NNN must be between 1 and 999.</td> </tr> <tr> <td align="right" valign="top"><b>?</b></td><td width="20"></td> <td>A question mark that is not followed by a number holds a spot for the next unused parameter.</td> </tr> <tr> <td align="right" valign="top"><b>:</b><i>AAAA</i></td><td width="20"></td> <td>A colon followed by an identifier name holds a spot for a named parameter with the name AAAA. Named parameters are also numbered. The number assigned is the next unused number. To avoid confusion, it is best to avoid mixing named and numbered parameters.</td> </tr> <tr> <td align="right" valign="top"><b>$</b><i>AAAA</i></td><td width="20"></td> <td>A dollar-sign followed by an identifier name also holds a spot for a named parameter with the name AAAA. The identifier name in this case can include one or more occurances of "::" and a suffix enclosed in "(...)" containing any text at all. This syntax is the form of a variable name in the Tcl programming language.</td> </tr> </table> </blockquote> <p>Parameters that are not assigned values using <a href="capi3ref.html#sqlite3_bind_int">sqlite3_bind</a> are treated as NULL.</p> <a name="like"></a> <p>The LIKE operator does a pattern matching comparison. The operand to the right contains the pattern, the left hand operand contains the string to match against the pattern. } puts "A percent symbol [Operator %] in the pattern matches any |
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1009 1010 1011 1012 1013 1014 1015 | puts { The LIKE operator is not case sensitive and will match upper case characters on one side against lower case characters on the other. (A bug: SQLite only understands upper/lower case for 7-bit Latin characters. Hence the LIKE operator is case sensitive for 8-bit iso8859 characters or UTF-8 characters. For example, the expression <b>'a' LIKE 'A'</b> is TRUE but | | > > | | > > > | | > > > > > > > > > | 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 | puts { The LIKE operator is not case sensitive and will match upper case characters on one side against lower case characters on the other. (A bug: SQLite only understands upper/lower case for 7-bit Latin characters. Hence the LIKE operator is case sensitive for 8-bit iso8859 characters or UTF-8 characters. For example, the expression <b>'a' LIKE 'A'</b> is TRUE but <b>'æ' LIKE 'Æ'</b> is FALSE.).</p> <p>The infix LIKE operator is implemented by calling the user function <a href="#likeFunc"> like(<i>X</i>,<i>Y</i>)</a>. If an ESCAPE clause is present, it adds a third parameter to the function call. If the functionality of LIKE can be overridden by defining an alternative implementation of the like() SQL function.</p> </p> <a name="glob"></a> <p>The GLOB operator is similar to LIKE but uses the Unix file globbing syntax for its wildcards. Also, GLOB is case sensitive, unlike LIKE. Both GLOB and LIKE may be preceded by the NOT keyword to invert the sense of the test. The infix GLOB operator is implemented by calling the user function <a href="#globFunc"> glob(<i>X</i>,<i>Y</i>)</a> and can be modified by overriding that function.</p> <a name="regexp"></a> <p>The REGEXP operator is a special syntax for the regexp() user function. No regexp() user function is defined by default and so use of the REGEXP operator will normally result in an error message. If a user-defined function named "regexp" is defined at run-time, that function will be called in order to implement the REGEXP operator.</p> <p>A column name can be any of the names defined in the CREATE TABLE statement or one of the following special identifiers: "<b>ROWID</b>", "<b>OID</b>", or "<b>_ROWID_</b>". These special identifiers all describe the unique random integer key (the "row key") associated with every row of every table. |
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1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 | <p>When a SELECT appears within an expression but is not the right operand of an IN operator, then the first row of the result of the SELECT becomes the value used in the expression. If the SELECT yields more than one result row, all rows after the first are ignored. If the SELECT yields no rows, then the value of the SELECT is NULL.</p> <p>Both simple and aggregate functions are supported. A simple function can be used in any expression. Simple functions return a result immediately based on their inputs. Aggregate functions may only be used in a SELECT statement. Aggregate functions compute their result across all rows of the result set.</p> <p>The functions shown below are available by default. Additional | > > > > | 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 | <p>When a SELECT appears within an expression but is not the right operand of an IN operator, then the first row of the result of the SELECT becomes the value used in the expression. If the SELECT yields more than one result row, all rows after the first are ignored. If the SELECT yields no rows, then the value of the SELECT is NULL.</p> <p>A CAST expression changes the datatype of the <expr> into the type specified by <type>. <type> can be any non-empty type name that if valid for the type in a column definition of a CREATE TABLE statement.</p> <p>Both simple and aggregate functions are supported. A simple function can be used in any expression. Simple functions return a result immediately based on their inputs. Aggregate functions may only be used in a SELECT statement. Aggregate functions compute their result across all rows of the result set.</p> <p>The functions shown below are available by default. Additional |
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