. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 607 13.7.1. The Mapping Rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . expression: Chapter 3. Data Types and Subtypes 61 2 + CAST('1' AS SMALLINT) The exception to the rule is during string concatenation. Implicit Conversion During String Concatenation When multiple data NULL and true → NULL Chapter 4. Common Language Elements 82 NULL and NULL → NULL  As a basic rule-of-thumb, if applying TRUE instead of NULL produces a different result than applying FALSE, then

still not sure what to choose (maybe you find all this tech talk a little overwhelming), use this rule of thumb: • On Windows, choose Superserver. Firebird 2.0 and 2.1 Quick Start 6 • On Linux, just who has filesystem-level write access to a database file can corrupt it or totally destroy it. As a rule, only the Firebird server process should have access to the database files. Users don't need, and to any objects within the database. Disable Classic local mode on Linux An exception to the above rule is the so-called local or embedded access mode of Firebird Classic Server on Linux. This mode requires

you will need to write it as a CAST expression: 2 + CAST('1' AS SMALLINT) The exception to the rule is during string concatenation. Implicit Conversion During String Concatenation When multiple data clause like this: select a, b, c from TA join TB on TA.a = TB.a; There is one exception to this rule: with named columns joins and natural joins, the unqualified field name of a column taking part in number, in the SELECT list, of an expression (column) that contains no aggregate function A general rule of thumb is that every non-aggregate item in the SELECT list must also be in the GROUP BY list. You

credentials checked. This can be especially disastrous if it concerns the security database! As a rule, only the Firebird server process should have access to the database files. Users don’t need, and the allowed type of access (if at all) to any objects within the database. As a relaxation of this rule, most Firebird configurations allow users to create and use databases in their own filesystem space machine. Shares, mapped drives or (on Unix) mounted SMB (Samba) file systems will not work. The same rule applies to any databases that you create or use. Connecting to a Firebird database requires — implicit

IN() list, write expressions like “if ( MyField = NULL ) then…”, and so on. However, as a general rule you should not make use of these new possibilities! In almost every thinkable situation, such use are summed and the sum divided by the number of non-NULL fields. There is one exception to this rule: COUNT(*) returns the count of all rows, even rows whose fields are all NULL. But COUNT(FieldName) survive without you even receiving a warning. So again: make sure that your existing rows obey the new rule immediately after adding the constrained column. The “default” trick won’t work here; you’ll just

guide.  The information provided in this section is for educational purposes only. As a general rule, you should leave system tables alone. Don’t attempt to create or alter generators by writing to

machine. Shares, mapped drives or (on Unix) mounted SMB (Samba) filesystems will not work. The same rule applies to any databases that you create. There are two elements to a TCP/IP connection string: the

doesn’t work for the Firebird utilities either. • Databases are all single file databases. The last rule applies to my installation only and means that the following simple backup script will work. If multiple

space, so record 1, for example, might appear in the “wrong” place in a dump as above.  This is a rule of relational databases, you can never know the order that data will be returned by a SELECT statement

RDB$MATCH_OPTION CHAR(7) Не используется. Текущим значением является FULL во всех случаях. RDB$UPDATE_RULE CHAR(11) Действия по ссылочной целостности, применимые к данному внешнему ключу, когда изменяется таблиц 676 Наименование столбца Тип данных Описание CASCADE, SET NULL, SET DEFAULT. RDB$DELETE_RULE CHAR(11) Действия по ссылочной целостности, применимые к данному внешнему ключу, когда удаляется первичный