For users upgrading from Firebird 2.1, this chapter lists the SQL additions and changes in Firebird 2.5 and 2.5.1, with links to the corresponding sections. If you come from an earlier version or are new to Firebird, you may want to skip this chapter.

• Newly reserved word: SIMILAR, SQLSTATE (2.5.1).
• New keywords: AUTONOMOUS, BIN_NOT, CALLER, CHAR_TO_UUID, COMMON, DATA, FIRSTNAME, GRANTED, LASTNAME, MAPPING, MIDDLENAME, OS_NAME, SOURCE, TWO_PHASE and UUID_TO_CHAR.
• No longer reserved, but still keywords: ACTIVE, AFTER, ASC, ASCENDING, AUTO, BEFORE, COLLATION, COMMITTED, COMPUTED, CONDITIONAL, CONTAINING, CSTRING, DATABASE, DESC, DESCENDING, DESCRIPTOR, DO, DOMAIN, ENTRY_POINT, EXCEPTION, EXIT, FILE, GEN_ID, GENERATOR, IF, INACTIVE, INPUT_TYPE, ISOLATION, KEY, LENGTH, LEVEL, MANUAL, MODULE_NAME, NAMES, OPTION, OUTPUT_TYPE, OVERFLOW, PAGE, PAGE_SIZE, PAGES, PASSWORD, PRIVILEGES, PROTECTED, READ, RESERV, RESERVING, RETAIN, SCHEMA, SEGMENT, SHADOW, SHARED, SINGULAR, SIZE, SNAPSHOT, SORT, STABILITY, STARTING, STARTS, STATEMENT, STATISTICS, SUB_TYPE, SUSPEND, TRANSACTION, UNCOMMITTED, WAIT, WORK and WRITE.
• No longer reserved and not keywords: AUTODDL, BASE_NAME, BASED, BLOBEDIT, BUFFER, CHECK_POINT_LENGTH, COMPILETIME, CONTINUE, DB_KEY, DEBUG, DESCRIBE, DISPLAY, ECHO, EDIT, EVENT, EXTERN, FOUND, GOTO, GROUP_COMMIT_, HELP, IMMEDIATE, INDICATOR, INIT, INPUT, ISQL, LC_MESSAGES, LC_TYPE, LEV, LOG_BUFFER_SIZE, MAX_SEGMENT, MAXIMUM, MESSAGE, MINIMUM, NOAUTO, NUM_LOG_BUFFERS, OUTPUT, PAGELENGTH, PREPARE, PUBLIC, QUIT, RETURN, RUNTIME, SHELL, SHOW, SQLERROR, SQLWARNING, STATIC, TERMINATOR, TRANSLATE, TRANSLATION, VERSION, WAIT_TIME and WHENEVER.

Changed since Firebird 2.1:

• Hexadecimal notation for numerals
• Hexadecimal notation for "binary" strings

Changed since Firebird 2.1:

• SQL_NULL data type
• GB18030 character set, WIN_1258 alias
• UNICODE_CI_AI collation for UTF8, GB18030 collation for GB18030

Changed since Firebird 2.1:

• ALTER CHARACTER SET (set default collation for charset)
• NUMERIC-SORT attribute for Unicode collations
• Default collation for the database
• Classic Server: Altered procedure immediately visible to other clients
• ALTER COLUMN also for generated (computed) columns
• ALTER COLUMN ... TYPE no longer fails if column is used in trigger or SP
• Views can select from stored procedures
• Views can infer column names from derived tables or GROUP BY
• Column list for UNION-based views no longer mandatory
• ALTER VIEW
• CREATE OR ALTER VIEW

Changed since Firebird 2.1:

• UPDATE statement: changed SET semantics

Changed since Firebird 2.1:

• TYPE OF COLUMN in variable and parameter declarations?
• EXECUTE STATEMENT
  • Improved performance?
  • WITH {AUTONOMOUS|COMMON} TRANSACTION?
  • WITH CALLER PRIVILEGES?
  • ON EXTERNAL [DATA SOURCE]?
  • AS USER, PASSWORD and ROLE?
  • Parameterized statements?
• IN AUTONOMOUS TRANSACTION
• Subqueries as PSQL expressions

Changed since Firebird 2.1:

• ALTER ROLE
• GRANTED BY clause
• REVOKE ALL ON ALL
• The RDB$ADMIN role
• AUTO ADMIN MAPPING
• SQL user management commands:
  • CREATE USER
  • ALTER USER
  • DROP USER

Changed since Firebird 2.1:

• SQLCODE deprecated (2.5.1)
• SQLSTATE context variable (2.5.1)

Changed since Firebird 2.1:

• SIMLAR TO: Regular expressions?

Changed since Firebird 2.1:

• LIST() separator may be any string expression?

Changed since Firebird 2.1:

• CAST() as TYPE OF COLUMN?
• DATEADD: New unit WEEK. Sub-DAY units allowed with DATEs.?
• DATEDIFF: New unit WEEK. Sub-DAY units allowed with DATEs.?
• CHAR_TO_UUID()?
• LOG() behaviour improved?
• LOG10() behaviour improved?
• LPAD() now returns VARCHAR of exact end length?
• RPAD() now returns VARCHAR of exact end length?
• UUID_TO_CHAR()?