Whether the creation of a new sequence DB2 sequence in DB2 and Oracle contains double quotation marks causes a production system problem www.2cto.com create sequence x3; -- run successfully create sequence "x3" -- run successfully (a sequence named "x3" is actually created and can be accessed using X3) values Nextval for x3 -- run successfully, value: 1 values prevval for X3 -- execution successful, value: 1 create sequence Y3; -- execution successful, you can use Y3, y3, or "Y3" to access create sequence "Y3" -- the execution fails and an error "values Nextval for Y3" is reported. -- the execution is successful, the value is 1 values Nextval for y3 -- execute the command, and the value is 2 create Sequence z3; -- execution successful create sequence "z3" -- execution successful (actually a sequence named "z3" is created, which is enclosed by quotation marks) -- values prevval for z3 -- error: values Nextval for z3 is returned because no value exists. -- execution successful; Value: 1 values Nextval for z3 -- execution successful, value: 2 values Nextval for "z3" -- execution successful; Value: 1 ------------------------------------------------------------- ORACLE sequence create sequence x3; -- create sequence "x3" -- the execution is successful (it indicates that the sequence is created in oracle. When there are lower-case letters in quotation marks, the quotation marks are different from those without quotation marks) -- select x3.prevval from dual -- error -- select X3.prevval from dual -- error select x3.Nextval from dual -- execution success value: 1 select x3.Nextval from dual -- execution success value: 2 select X3.Nextval from dual -- execution the successful value is 3, which is actually the sequence select "x3" of x3 ". nextval from dual -- the execution success value is 1 select "x3 ". nextval from dual -- the execution success value is 2 ------------------------------- create sequence Y3; -- the execution is successful. create sequ Ence "Y3" -- failed to execute. An error is returned, indicating that a sequence already exists. (This indicates that if sequence is created in oracle in uppercase, it is the same as creating a sequence with quotation marks .) Select Y3.nextval from dual -- the execution success value is 1 select "Y3 ". nextval from dual -- the execution success value is 2 --------------------------------- create sequence "A" -- OK select "". nextval from dual -- OK select. nextval from dual -- OK select. nextval from dual -- OK select "". nextval from dual -- OK select "". nextval from dual -- error ------------------------------- create sequence "B" -- OK select "B ". nextval from dual -- OK select B. nextval from dual -- error select B. nextval from dual -- error select "B ". nextval from dual -- error select "B ". nextval from dual -- OK ------------------------------- create sequence "a" select. nextval from dual -- error select. nextval from dual -- error select "". nextval from dual -- OK select "". nextval from dual -- error ------------------------------- create sequence "B" select B. nextval from dual -- OK select B. nextval from dual -- OK select "B ". nextval from dual -- error select "B ". nextval from dual -- OK drop sequence B -- OK drop sequence a -- error drop sequence "a" -- OK create sequence "B" -- OK drop sequence B -- OK create sequence "B "-- OK drop sequence "B" -- error drop sequence B -- OK ---------------------------------------------------------------