Development in Oracle over time
Development in Oracle over time
The Update in an Oracle SQL statement can be used with SEQUENCE to Update the continuous numbers of values of a field without having to traverse and Update database records one by one using a cursor. For example, update sample set id = seq_id.nextval;
The select statement in Oracle allows the use of case statements. Example: select col1, case when col1> 1 then 'exist 'else' no 'end col2 from tab;
In PROC programming, compile the PROC source file into a PROC file Statement (optional): proc iname = file. cpp oname = file. cxx threads = yes;
// Convert the proc file
Proc iname = file. cpp oname = file. cxx threads = yes
// Proc lib Library File
Clntsh
// Oracle lib path
/Home/oracle/u01/app/oracle/product/10.1.0/db_1/lib
// Execute the statement before gdb
Ulimit-c unlimited
// Gdb instance
Gdb test core.9959
Type usage and conversion in C ++ encoding:
Const string & iv_value
Const char * lv_value
Lv_value = iv_value.c_str ()
Const string & iv_value
Char * lv_value
Lv_value = (char *) iv_value.c_str ()
Determines whether the string variable is null.
String ls_value
If (true = ls_value.empty ()){}
The pointer is null.
Char * lc_value
If (NULL = lc_value ){}
