SQL share (AND the PRIOR DBMS_RANDOM. The VALUE IS NOT NULL) IS redundant-CodePudding

SQL share (AND the PRIOR DBMS_RANDOM. The VALUE IS NOT NULL) IS redundant, excluding influential?

SELECT 'TEST2' TABLE_NAME,
REGEXP_SUBSTR (COL1, COL2, '[^,] +' 1, LEVEL) COLUMN_NAME FROM DUAL
CONNECT BY LEVEL

SELECT 'TEST2' TABLE_NAME,
REGEXP_SUBSTR (COL1, COL2, '[^,] +' 1, LEVEL) COLUMN_NAME FROM DUAL
CONNECT BY LEVEL CodePudding user response:

Good question, encouraging;

If only for a line of data, to be apart, so this condition can be removed;
Just try to two (or more rows of data) :

Select col1, col2 from dual
Union all
Select 'col3 col4,' the from dual

CodePudding user response:

To learn...

CodePudding user response:

Try not to know.

CodePudding user response:

Learning

CodePudding user response:

Learning,,,,,,,,,

CodePudding user response:

Learning, pass by,

CodePudding user response:

 
As with TEST2 
(select 'COL1, COL2 as col_name 
The from dual 
Union all 
Select 'col3 col4,' 
The from dual) 

SELECT 'TEST2' TABLE_NAME, 
REGEXP_SUBSTR (TEST2 col_name, '[^,] +' 1, LEVEL) COLUMN_NAME 
The FROM DUAL 
CONNECT BY LEVEL & lt;=LENGTH (REGEXP_REPLACE (TEST2 col_name, '[^,] +')) + 1 
AND the PRIOR sysdate IS NOT NULL;

An error Test2. Invalid col_name definition,,, where is wrong

CodePudding user response:

refer to the eighth floor q12344566789 response:

 
As with TEST2 
(select 'COL1, COL2 as col_name 
The from dual 
Union all 
Select 'col3 col4,' 
The from dual) 

SELECT 'TEST2' TABLE_NAME, 
REGEXP_SUBSTR (TEST2 col_name, '[^,] +' 1, LEVEL) COLUMN_NAME 
The FROM DUAL 
CONNECT BY LEVEL & lt;=LENGTH (REGEXP_REPLACE (TEST2 col_name, '[^,] +')) + 1 
AND the PRIOR sysdate IS NOT NULL;

Error Test2. Col_name invalid definition,,, it is a wrong place

@ the net of selling fruits help have a look

CodePudding user response:

references 9 f q12344566789 response:

Quote: refer to the eighth floor q12344566789 response:

 
As with TEST2 
(select 'COL1, COL2 as col_name 
The from dual 
Union all 
Select 'col3 col4,' 
The from dual) 

SELECT 'TEST2' TABLE_NAME, 
REGEXP_SUBSTR (TEST2 col_name, '[^,] +' 1, LEVEL) COLUMN_NAME 
The FROM DUAL 
CONNECT BY LEVEL & lt;=LENGTH (REGEXP_REPLACE (TEST2 col_name, '[^,] +')) + 1 
AND the PRIOR sysdate IS NOT NULL;

Error Test2. Col_name invalid definition,,, it is a wrong place

@ the net of selling fruits look

I bug again,,, from test2 is not ready,, silly off my

CodePudding user response:

references to the tenth floor q12344566789 response:

I bug again,,, from test2 is not ready,, silly off my

CodePudding user response:

11 references wmxcn2000 response:

A great god, and I still have a question,
The result is

 
As with TEST2 
(select 'COL1, COL2 as col_name 
The from dual 
Union all 
Select 'col3 col4,' 
The from dual) 

SELECT distinct 'TEST2' TABLE_NAME, 
REGEXP_SUBSTR (col_name, '[^,] +' 1, LEVEL) COLUMN_NAME 
The FROM TEST2 
CONNECT BY LEVEL & lt;=LENGTH (REGEXP_REPLACE (col_name, '[^,] +')) + 1 
 and the PRIOR DBMS_RANDOM. The VALUE IS NOT NULL;

 
TABLE_NAME COLUMN_NAME 
1 TEST2 COL2 
2 TEST2 COL1 
3 TEST2 col4 
4 TEST2 col3

With a distinct, isn't it feel a little YingCou ah, in addition to remove the red place, the result is the same,,

CodePudding user response:

The

refer to 12 floor q12344566789 reply:

add a distinct, feels a bit YingCou ah, in addition to remove the red place, the result is the same,,

 
- add a PK list 
As with TEST2 
(select 'COL1, COL2 as col_name, 1 id 
The from dual 
Union all 
Select ', col3 col4, 2 
The from dual 
) 

SELECT 'TEST2' TABLE_NAME, 
REGEXP_SUBSTR (col_name, '[^,] +' 1, LEVEL) COLUMN_NAME 
The FROM TEST2 
CONNECT BY the PRIOR id=id 
And LEVEL & lt;=regexp_count (col_name, ', ') + 1 
VALUE IS NOT NULL and the PRIOR DBMS_RANDOM.

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