The development under Oracle is cumulative

Update in the Oracle SQL statement can be used in conjunction with SEQUENCE to update the value of a field consecutively without using a cursor to iterate through the updated database record. For example, update sample set id = seq_id.nextval;

The select statement in Oracle allows the use of case statements. Examples are select col1,case when col1 > 1 then 'exist' else 'no' end col2 from tab;

PROC program compiles PROC source file into PROC file statement (with optional parameters) : proc iname= file.cpp oname= file.cxx threads=yes;

//proc file conversion
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()

Determine that the string class variable is empty
string ls_value
if (true == ls_value.empty()){}

Determines that the pointer is null
char *lc_value
if(NULL == lc_value){}