Firebird 2.1 Language Reference Update

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Result type: INTEGER Syntax: BIT_LENGTH (str) Internal functions BLOB support: Since Firebird 2.1, this function fully supports text BLOBs of any length and character set. Examples: select bit_length('Hello!') from rdb$database -- returns 48 select bit_length(_iso8859_1 'Grüß di!') from rdb$database -- returns 64: ü and ß take up one byte each in ISO8859_1 select bit_length (cast (_iso8859_1 'Grüß di!' as varchar(24) character set utf8)) from rdb$database -- returns 80: ü and ß take up two bytes each in UTF8 select bit_length (cast (_iso8859_1 'Grüß di!' as char(24) character set utf8)) from rdb$database -- returns 208: all 24 CHAR positions count, and two of them are 16-bit See also: OCTET_LENGTH(), CHARACTER_LENGTH Available in: DSQL, ESQL, PSQL Added in: IB Changed in: 2.0, 2.1 CAST() Description: CAST converts an expression to the desired datatype or domain. If the conversion is not possible, an error is raised. Result type: User-chosen. Syntax: CAST (expression AS {datatype | [TYPE OF] domain}) Shorthand syntax: Alternative syntax, supported only when casting a string literal to a DATE, TIME or TIMESTAMP: datatype 'date/timestring' This syntax was already available in InterBase, but was never properly documented. 129
Examples: A full-syntax cast: Internal functions select cast ('12' || '-June-' || '1959' as date) from rdb$database A shorthand string-to-date cast: update People set AgeCat = 'Old' where BirthDate < date '1-Jan-1943' Notice that you can drop even the shorthand cast from the example above, as the engine will understand from the context (comparison to a DATE field) how to interpret the string: update People set AgeCat = 'Old' where BirthDate < '1-Jan-1943' But this is not always possible. The cast below cannot be dropped, otherwise the engine would find itself with an integer to be subtracted from a string: select date 'today' - 7 from rdb$database The following table shows the type conversions possible with CAST. Table 12.1. Possible CASTs From To Numeric types Numeric types [VAR]CHAR BLOB [VAR]CHAR BLOB DATE TIME 130 [VAR]CHAR BLOB Numeric types DATE TIME TIMESTAMP [VAR]CHAR BLOB TIMESTAMP TIMESTAMP [VAR]CHAR BLOB DATE TIME Keep in mind that sometimes information is lost, for instance when you cast a TIMESTAMP to a DATE. Also, the fact that types are CAST-compatible is in itself no guarantee that a conversion will succeed. “CAST(123456789 as SMALLINT)” will definitely result in an error, as will “CAST('Judgement Day' as DATE)”. Casting input fields: Since Firebird 2.0, you can cast statement parameters to a datatype: cast (? as integer)
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Firebird 2.1 Language Reference Upd
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Table of Contents 1. Introduction .
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Firebird 2.1 Language Ref. Update F
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Firebird 2.1 Language Ref. Update A
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Firebird 2.1 Language Ref. Update s
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Chapter 1 Introduction Subject matt
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Chapter 2 Reserved words and keywor
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LOCK LOG LOG10 LPAD MATCHED MATCHIN
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Chapter 3 Available in: DSQL, PSQL
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Example: select name, age, case upp
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Data types and subtypes • Partial
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Added in: 1.0, 1.5, 1.5.1, 2.0, 2.1
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Chapter 5 DDL statements The statem
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With a special attribute (case-sens
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DIFFERENCE FILE parameter Added in:
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CREATE DOMAIN Available in: DSQL, E
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Example: DDL statements create exce
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Syntax: Example: ALTER EXTERNAL FUN
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DDL statements -- the following que
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DDL statements PROCEDURE A stored p
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DDL statements Description: Firebir
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DDL statements NOT NULL in variable
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CREATE GENERATOR Available in: DSQL
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Better alternative: DROP SEQUENCE D
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) DDL statements lastname varchar(2
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USING INDEX subclause Available in:
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ALTER COLUMN: SET DEFAULT Available
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UNIQUE constraints now allow NULLs
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Example: DDL statements create trig
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Multi-action triggers Added in: 1.5
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NOT NULL in variable declarations C
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DDL statements Restriction on recre
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DDL statements got a chance to put
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ORDER BY Available in: DSQL, PSQL A
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DML statements ROWS can also be use
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DML statements COLLATE in variable
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The same call in ESQL (with obligat
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DML statements Description: A SELEC
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DML statements Aggregate functions
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Syntax: Example: Notes: ::= DML
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DML statements select d.dept_no, d.
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DML statements FIRST and SKIP are b
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DML statements select strlen(lastna
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DML statements Description: A natur
Page 90 and 91: DML statements • Only non-negativ
Page 92 and 93: Example: DML statements plan (MyTab
Page 94 and 95: UNIONs in subqueries Changed in: 2.
Page 96 and 97: Restrictions DML statements • The
Page 98 and 99: DML statements Description: Limits
Page 100 and 101: Chapter 7 Available in: DSQL Added
Page 102 and 103: Transaction control statements If t
Page 104 and 105: Transaction control statements •
Page 106 and 107: Chapter 8 PSQL statements PSQL - Pr
Page 108 and 109: PSQL statements • If sql_datatype
Page 110 and 111: Warning PSQL statements If you chan
Page 112 and 113: PSQL statements exception ex_bad_ty
Page 114 and 115: PSQL statements as declare variable
Page 116 and 117: Examples: PSQL statements thoroughl
Page 118 and 119: leave; end end c = 0; PSQL statemen
Page 120 and 121: Chapter 9 Available in: DSQL, PSQL
Page 122 and 123: Changed in: 2.0 Context variables D
Page 124 and 125: Context variables its execution was
Page 126 and 127: Context variables Description: OLD
Page 128 and 129: Chapter 10 Changed in: 2.0 Operator
Page 130 and 131: UNION as subselect Changed in: 2.0
Page 132 and 133: Chapter 11 Aggregate functions Aggr
Page 134 and 135: Chapter 12 Available in: DSQL, PSQL
Page 136 and 137: • If the argument is NULL, NULL i
Page 138 and 139: Result type: INTEGER or BIGINT Synt
Page 142 and 143: Internal functions This gives you c
Page 144 and 145: Available in: DSQL, PSQL Added in:
Page 148 and 149: Example: The equivalent CASE constr
Page 150 and 151: WEEK Bug alert Internal functions M
Page 152 and 153: Added in: 2.1 Internal functions De
Page 154 and 155: Internal functions • If x is nega
Page 156 and 157: Examples: Internal functions lpad (
Page 158 and 159: Internal functions This will return
Page 160 and 161: Internal functions overlay ('Goodby
Page 164 and 165: Internal functions Description: Cre
Page 166 and 167: Internal functions reverse ('Was it
Page 168 and 169: Added in: 2.1 Internal functions De
Page 170 and 171: Syntax: SINH (number) Important Int
Page 174 and 175: Notes: Internal functions • If th
Page 176 and 177: Description: Returns the arc cosine
Page 178 and 179: Declaration: External functions (UD
Page 180 and 181: Library: ib_udf Changed in: 1.0, 2.
Page 182 and 183: Better alternative: Internal functi
Page 184 and 185: External functions (UDFs) Descripti
Page 186 and 187: Syntax: cot (angle) Declaration: Ex
Page 188 and 189: Declaration: External functions (UD
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Library: ib_udf Added in: IB Change
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Changed in: 1.5, 1.5.2, 2.0 Better
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External functions (UDFs) DECLARE E
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See sright. Library: fbudf Added in
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Notes: External functions (UDFs) Fo
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Syntax: sign (number) Declaration:
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Library: fbudf Added in: 1.0 (Win),
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Notes: External functions (UDFs) th
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Better alternative: Internal functi
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Appendix A: Notes Character set NON
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Table A.1. How TPB settings affect
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Notes A note on CSTRING parameters
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Notes Maximum number of indices in
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Document History DDL statements ::
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Document History Internal functions
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Appendix C: License notice The cont
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Firebird 2.1 Language Reference Update

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