Firebird 2.1 Language Reference Update

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Syntax: SINH (number) Important Internal functions If the external function SINH is declared in your database, it will override the internal function. To make the internal function available, DROP or ALTER the external function (UDF). Available in: DSQL, PSQL Added in: 2.1 Description: Returns the square root of the argument. Result type: DOUBLE PRECISION Syntax: SQRT (number) Important SQRT() If the external function SQRT is declared in your database, it will override the internal function. To make the internal function available, DROP or ALTER the external function (UDF). Available in: DSQL, PSQL Added in: 1.0 Changed in: 2.0, 2.1 SUBSTRING() Description: Returns a string's substring starting at the given position, either to the end of the string or with a given length. Result type: VARCHAR(n) or BLOB Syntax: SUBSTRING (str FROM startpos [FOR length]) This function returns the substring starting at character position startpos (the first position being 1). Without the FOR argument, it returns all the remaining characters in the string. With FOR, it returns length characters or the remainder of the string, whichever is shorter. 159
Internal functions In Firebird 1.x, startpos and length must be integer literals. In 2.0 and above they can be any valid integer expression. Starting with Firebird 2.1, this function fully supports binary and text BLOBs of any length and character set. If str is a BLOB, the result is also a BLOB. For any other argument type, the result is a VARCHAR(n). Previously, the result type used to be CHAR(n) if the argument was a CHAR(n) or a string literal. For non-BLOB arguments, the width of the result field is always equal to the length of str, regardless of startpos and length. So, substring('pinhead' from 4 for 2) will return a VARCHAR(7) containing the string 'he'. If any argument is NULL, the result is NULL. Example: Bugs • If str is a BLOB and the length argument is not present, the output is limited to 32767 characters. Workaround: with long BLOBs, always specify char_length(str) – or a sufficiently high integer – as the third argument, unless you are sure that the requested substring fits within 32767 characters. • A bug in Firebird 2.0 which caused the function to return “false emptystrings” if startpos or length was NULL, has been fixed. insert into AbbrNames(AbbrName) select substring(LongName from 1 for 3) from LongNames Warning When used on a BLOB, this function may need to load the entire object into memory. Although it does try to limit memory consumption, this may affect performance if huge BLOBs are involved. Available in: DSQL, PSQL Added in: 2.1 TAN() Description: Returns an angle's tangent. The argument must be given in radians. Result type: DOUBLE PRECISION Syntax: TAN (angle) Important If the external function TAN is declared in your database, it will override the internal function. To make the internal function available, DROP or ALTER the external function (UDF). 160
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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
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DML statements • Only non-negativ
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Example: DML statements plan (MyTab
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UNIONs in subqueries Changed in: 2.
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Restrictions DML statements • The
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DML statements Description: Limits
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Chapter 7 Available in: DSQL Added
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Transaction control statements If t
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Transaction control statements •
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Chapter 8 PSQL statements PSQL - Pr
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PSQL statements • If sql_datatype
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Warning PSQL statements If you chan
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PSQL statements exception ex_bad_ty
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PSQL statements as declare variable
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Examples: PSQL statements thoroughl
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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 140 and 141: Result type: INTEGER Syntax: BIT_LE
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 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
Page 190 and 191: Library: ib_udf Added in: IB Change
Page 192 and 193: Changed in: 1.5, 1.5.2, 2.0 Better
Page 194 and 195: External functions (UDFs) DECLARE E
Page 196 and 197: See sright. Library: fbudf Added in
Page 198 and 199: Notes: External functions (UDFs) Fo
Page 200 and 201: Syntax: sign (number) Declaration:
Page 202 and 203: Library: fbudf Added in: 1.0 (Win),
Page 204 and 205: Notes: External functions (UDFs) th
Page 206 and 207: Better alternative: Internal functi
Page 208 and 209: Appendix A: Notes Character set NON
Page 210 and 211: Table A.1. How TPB settings affect
Page 212 and 213: Notes A note on CSTRING parameters
Page 214 and 215: Notes Maximum number of indices in
Page 216 and 217: Document History DDL statements ::
Page 218 and 219: 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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