Firebird 2.5 Language Reference
string literals or comments. Operator Syntax <operator> ::=operator> | operator> | operator> | operator> Chapter 2. SQL Language Structure concatentation operator> ::= "||" operator> ::= * | / | + | - | operator> ::= = | <> | != | ~= | ^= | > | < | >= | <= | !> | ~> | ^> | !< | ~< | ^< operator> ::= NOT Arithmetic operators The +, -, *, / characters used to calculate values Concatenation operator The || (“double-pipe”) operator used to concatenate strings Logical operators The reserved words NOT, AND and 0 码力 | 521 页 | 2.30 MB | 1 年前3Firebird Null Guide: NULL behaviour and pitfalls in Firebird SQL
never return NULL. 2.3. Assigning NULL Setting a field or variable to NULL is done with the ‘=’ operator, just like assigning values. You can also include NULL in an insert list or use it as input parameter You cannot — and should not — use the comparison operator ‘=’ to test if something is NULL… • …but you can — and often must — use the assignment operator ‘=’ to set something to NULL. 2.4. Testing DISTINCTness The above results can be generalised as follows for expressions with one type of binary boolean operator (and | or) and any number of operands: Disjunctions (“A or B or C or D or …”) 1. If at least one0 码力 | 69 页 | 479.63 KB | 1 年前3firebird 40 language reference
comments. Operator Syntax <operator> ::=operator> | operator> | operator> | operator> operator> ::= "||" operator> ::= * | / | + | - | operator> ::= = | <> | != | ~= | ^= | > | < | >= | <= | !> | ~> | ^> | !< | ~< | ^< operator> ::= NOT | AND | OR For more details values. For example, field1 OR field2 and NOT field1 are valid expressions. The IS Operator Predicates can use the operator Boolean IS [NOT] for matching. For example, field1 IS FALSE, or field1 IS NOT TRUE 0 码力 | 778 页 | 3.43 MB | 1 年前3firebird language reference 30 rus
комментариев. Синтаксис: <operator> ::=operator> | operator> | operator> | operator> operator> ::= {||} operator> ::= * | / | + | - | operator> ::= {=} | {<>} | {!=} | {~=} | {^=} | {>} | {<} | {>=} | {<=} | {!>} | {~>} | {^>} | {!<} | {~<} | {^<} {^<} operator> ::= NOT | AND | OR Подробнее об операторах см. Выражения. Комментарии В SQL скриптах, операторах SQL и PSQL модулях могут встречаться 0 码力 | 719 页 | 3.98 MB | 1 年前3firebird 30 sprachreferenz
Operatorsyntax <operator> ::=operator> | operator> | operator> | operator> operator> ::= "||" operator> ::= * * | / | + | - | operator> ::= = | <> | != | ~= | ^= | > | < | >= | <= | !> | ~> | ^> | !< | ~< | ^< operator> ::= NOT | AND | OR Weitere Informationen zu Operatoren finden NOT field1 gültige Ausdrücke. Chapter 3. Datentypen und Untertypen 38 Der IS-Operator Prädikate können den Operator Boolean IS [NOT] zum Abgleich verwenden. Zum Beispiel field1 IS FALSE oder field1 0 码力 | 701 页 | 3.12 MB | 1 年前3Firebird 2.1 ErrorCodes
dyn_dependency_exists Column @1 from table @2 is referenced in @3 -401 335544647 invalid_operator Invalid comparison operator for find operation -402 335544368 segstr_no_op Attempted invalid operation on a BLOB BLOB data types not allowed in computed field -607 336397214 dsql_only_can_subscript_array Scalar operator used on field @1 which is not an array -612 336068812 dyn_domain_name_exists Cannot rename domain0 码力 | 31 页 | 103.24 KB | 1 年前3firebird 5 quickstartguide
symbols (“||”, or a pair of ASCII 124 without space between). In SQL, the “+” symbol is an arithmetic operator, and it will cause an error if you attempt to use it for concatenating strings. The following expression Notice that if neither operand is NULL, IS DISTINCT works exactly like the “<>” operator, and IS NOT DISTINCT like the “=” operator. IS DISTINCT and IS NOT DISTINCT always return true or false, never NULL0 码力 | 49 页 | 396.21 KB | 1 年前3Firebird 2 QuickStart
“pipe” symbols (ASCII 124, in a pair with no space between). In SQL, the “+” symbol is an arithmetic operator and it will cause an error if you attempt to use it for concatenating strings. The following expression Notice that if neither operand is NULL, DISTINCT works exactly like the “<>” operator, and NOT DISTINCT like the “=” operator. DISTINCT and NOT DISTINCT always return true or false, never NULL. Using0 码力 | 40 页 | 218.42 KB | 1 年前3Firebird 2 QuickStart German
in einem Paar mit keinem Leerzei- chen dazwischen). Das „+“ Symbol in SQL ist ein arithmetischer Operator und wird einen Fehler nach sich ziehen, wenn Sie versuchen, diesen für die Verkettung von Strings keiner der beiden Ausdrücke NULL ist, dann verhält sich DISTINCT wie der „<>“ Operator, und NOT DISTINCT wie der „=“ Operator. DISTINCT und NOT DISTINCT geben immer true oder false zurück und nie NULL.0 码力 | 37 页 | 207.22 KB | 1 年前3Firebird 1.5 ErrorCodes
Columnfrom table is referenced in -401 335544647 invalid_operator Invalid comparison operator for find operation -402 335544368 segstr_no_op Attempted invalid operation on a BLOB 0 码力 | 26 页 | 85.09 KB | 1 年前3
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