Oracle If-else Conditional Judgment structure

1. IF syntax

IF expression then    ... END IF;

For example:

Set Serverout ondeclare   v_name varchar2: = ' &name '; begin   if V_name= ' Kiki ' then      dbms_output.put_ Line (' login successful ');   End if;end;/--------execution results as follows-------Enter the value of name:  Kiki    2:    v_name varchar2: = ' &name '; new value    2:    v_name varchar2: = ' kiki '; login successful

2. IF: ELSE Syntax:

IF  Condition expression then  
...
ELSE
...
END IF;

For example:

Set Serverout ondeclare   v_name student.sname%type:= ' &name '; begin  if V_name= ' Kiki ' then      dbms_ Output.put_line (' Login successful! ');  else     dbms_output.put_line (' Login failed ');  End if;end;/--------execution results as follows-------Enter the value of name:  Kiki    2:    v_name student.sname%type:= ' &name '; new value    2:    v_name student.sname%type:= ' kiki '; Login failed

3. IF ... Elsif ... ELSE Nesting structure

IF condition expression then    ... elsif conditional expression then    ... ELSE    ... END  IF;

For example:

--1.if-else structure set Serverput  on-open Oracle's own output method Dbms_outputdeclare-declaration   v_name VARCHAR2: = ' &name ';-- Define variables that need to be entered manually   V_password number: = ' &password '; Begin--Start   if v_name= ' Kikiwen ' and v_password=123 then-- Conditional Judgment      dbms_output.put_line (' login succeeded ');--output statement   elsif v_name= ' Kiki ' and v_password=123 then      dbms_output.put_ Line (' Login ' | | | v_name | | ' Account Success ');   else      dbms_output.put_line (' Login failed! ' | | V_name | | ' Incorrect account or password ');   End if;end;--Finish/--------execution results as follows-------Enter a value for name:  Kiki    2:    v_name varchar2: = ' &name '; new value    2:    v_name varchar2: = ' kiki '; input password value:  123 Original Value    2:    v_name varchar2: = ' & Password '; new value    2:    v_name varchar2 (20): = 123; login Kiki account Successful

Oracle If-else Conditional Judgment structure