How to concatenate strings with padding in sqlite

StringSqliteString ConcatenationLeading Zero

String Problem Overview


I have three columns in an sqlite table:

    Column1    Column2    Column3
    A	       1	      1
    A	       1	      2
    A	       12	      2
    C	       13	      2
    B	       11	      2

I need to select Column1-Column2-Column3 (e.g. A-01-0001). I want to pad each column with a -

I am a beginner with regards to SQLite, any help would be appreciated

String Solutions


Solution 1 - String

> The || operator is "concatenate" - it joins together the two strings of > its operands.

From http://www.sqlite.org/lang_expr.html

For padding, the seemingly-cheater way I've used is to start with your target string, say '0000', concatenate '0000423', then substr(result, -4, 4) for '0423'.

Update: Looks like there is no native implementation of "lpad" or "rpad" in SQLite, but you can follow along (basically what I proposed) here: http://verysimple.com/2010/01/12/sqlite-lpad-rpad-function/

-- the statement below is almost the same as
-- select lpad(mycolumn,'0',10) from mytable

select substr('0000000000' || mycolumn, -10, 10) from mytable

-- the statement below is almost the same as
-- select rpad(mycolumn,'0',10) from mytable

select substr(mycolumn || '0000000000', 1, 10) from mytable

Here's how it looks:

SELECT col1 || '-' || substr('00'||col2, -2, 2) || '-' || substr('0000'||col3, -4, 4)

it yields

"A-01-0001"
"A-01-0002"
"A-12-0002"
"C-13-0002"
"B-11-0002"

Solution 2 - String

SQLite has a printf function which does exactly that:

SELECT printf('%s-%.2d-%.4d', col1, col2, col3) FROM mytable

Solution 3 - String

Just one more line for @tofutim answer ... if you want custom field name for concatenated row ...

SELECT 
  (
	col1 || '-' || SUBSTR('00' || col2, -2, 2) | '-' || SUBSTR('0000' || col3, -4, 4)
  ) AS my_column 
FROM
  mytable;

Tested on SQLite 3.8.8.3, Thanks!

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionAksharaView Question on Stackoverflow
Solution 1 - StringtofutimView Answer on Stackoverflow
Solution 2 - StringYakov GalkaView Answer on Stackoverflow
Solution 3 - StringMadan SapkotaView Answer on Stackoverflow