VARCHAR(10) alanına 29 karakter nasıl konur?

Firebird Cuma Şakası #6 (kaynak: https://t.me/firebirdsql)

Eski ama hâlâ güzel bir şaka: çok baytlı karakter setleriyle, bildirilenden daha fazla sembol eklemek mümkündür. Unicode öğrenin! :)

Keyfini çıkarın!

Code

C:\HQbird\Firebird25.in>isql
Use CONNECT or CREATE DATABASE to specify a database
SQL> create database "c:\databases\test1.fdb" user "SYSDBA" password "masterkey";
SQL> create table t2(v1 varchar(10) character set UNICODE_FSS);
SQL> insert into t2(v1) values('12345678901');
SQL> insert into t2(v1) values('123456789012');
SQL> insert into t2(v1) values('1234567890123');
SQL> insert into t2(v1) values('12345678901234');
SQL> insert into t2(v1) values('123456789012345');
SQL> insert into t2(v1) values('1234567890123456');
SQL> insert into t2(v1) values('12345678901234567');
SQL> insert into t2(v1) values('1234567890123456789101234');
SQL> insert into t2(v1) values('12345678901234567891012345');
SQL> insert into t2(v1) values('123456789012345678910123456');
SQL> insert into t2(v1) values('1234567890123456789101234567');
SQL> insert into t2(v1) values('12345678901234567891012345678');
SQL> insert into t2(v1) values('123456789012345678910123456789');  <--- 29 karakter!
SQL> insert into t2(v1) values('1234567890123456789101234567890');
Statement failed, SQLSTATE = 22001
arithmetic exception, numeric overflow, or string truncation
-string right truncation
SQL> create table t3(v1 varchar(10) character set UTF8);
SQL> insert into t2(v1) values('1234567890');
SQL> insert into t2(v1) values('12345678901');
SQL> insert into t2(v1) values('123456789012');
SQL> insert into t2(v1) values('123456789012345678');
SQL> insert into t2(v1) values('1234567890123456789');
SQL> insert into t2(v1) values('12345678901234567890');
SQL> insert into t2(v1) values('123456789012345678901');
SQL> insert into t2(v1) values('12345678901234567890123');
SQL> insert into t2(v1) values('1234567890123456789012345678');
SQL> insert into t2(v1) values('123456789012345678901234567890');
SQL> insert into t2(v1) values('1234567890123456789012345678901');
Statement failed, SQLSTATE = 22001
arithmetic exception, numeric overflow, or string truncation
-string right truncation
SQL>

2.5’te çalışıyor, 3.0’da utf8 ile farklı davranıyor

Code

SQL> create table t2(v1 varchar(10) character set UNICODE_FSS);
SQL> insert into t2(v1) values('12345678901');
SQL> insert into t2(v1) values('12345678901234567890');
SQL> insert into t2(v1) values('12345678901234567890123456789');
SQL> insert into t2(v1) values('123456789012345678901234567890');
SQL> insert into t2(v1) values('1234567890123456789012345678901');
Statement failed, SQLSTATE = 22001
arithmetic exception, numeric overflow, or string truncation
-string right truncation
-expected length 10, actual 30
SQL> create table t3(v1 varchar(10) character set utf8);
SQL> insert into t3(v1) values('1234567890');
SQL> insert into t3(v1) values('12345678901');
Statement failed, SQLSTATE = 22001
arithmetic exception, numeric overflow, or string truncation
-string right truncation
-expected length 10, actual 11
SQL>