. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 13.1. NULL <=> non-NULL conversions you didn’t ask for . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 13.4. Being prepared for undesired conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 13 first. This also applies to the UDFs that come with Firebird itself. 13.1. NULL <=> non-NULL conversions you didn’t ask for Teaching you how to declare, use, and write UDFs is outside the scope of this

........... 6 NULL <-> non-NULL conversions non demandées ............................................................................ 6 Soyez préparés aux conversions non voulues .................... dans la base d'abord. Ceci est aussi vrai pour les UDF livrées avec Firebird. NULL <-> non-NULL conversions non demandées Vous apprendre à déclarer, utiliser, et écrire des UDFs est hors du champ de ce ce guide. Toutefois, nous devons vous prévenir que les UDFs peuvent quelques fois effectuer des conversions de NULL non désirées. Cela va quelques fois convertir des entrées NULL en des valeurs régulières

time/timestamp with time zone is considered equal to another time/timestamp with time zone if their conversions to UTC are equivalent. For example, time '10:00 -02:00' and time '09:00 -03:00' are equivalent ('I have many friends' AS TYPE OF COLUMN TTT.S) FROM RDB$DATABASE; Conversions Possible for the CAST Function Table 15. Conversions with CAST From Data Type To Data Type Numeric types Numeric types code may stop working!  When you convert data types in a domain, you must not perform any conversions that may result in data loss. Also, for example, if you convert VARCHAR to INTEGER, check carefully

('I have many friends' AS TYPE OF COLUMN TTT.S) FROM RDB$DATABASE; Conversions Possible for the CAST Function Table 8. Conversions with CAST From Data Type To Data Type Numeric types Numeric types code may stop working!  When you convert data types in a domain, you must not perform any conversions that may result in data loss. Also, for example, if you convert VARCHAR to INTEGER, check carefully from a string: select date 'today' - 7 from rdb$database The following table shows the type conversions possible with CAST. Table 146. Possible Type-castings with CAST From To Numeric types Numeric

Scripts that manipulate data by selecting, inserting, updating, deleting or performing data conversions, are called Data Manipulation Language (DML) scripts. One of the most important tasks handled