Function zAutoColumn

modules/dasSQLITE/sqlite/shell.c:22792–22965

#endif

static char *zAutoColumn(const char *zColNew, sqlite3 **pDb, char **pzRenamed){
  /* Queries and D{D,M}L used here */
  static const char * const zTabMake = "\
CREATE TABLE ColNames(\
 cpos INTEGER PRIMARY KEY,\
 name TEXT, nlen INT, chop INT, reps INT, suff TEXT);\
CREATE VIEW RepeatedNames AS \
SELECT DISTINCT t.name FROM ColNames t \
WHERE t.name COLLATE NOCASE IN (\
 SELECT o.name FROM ColNames o WHERE o.cpos<>t.cpos\
);\
";
  static const char * const zTabFill = "\
INSERT INTO ColNames(name,nlen,chop,reps,suff)\
 VALUES(iif(length(?1)>0,?1,'?'),max(length(?1),1),0,0,'')\
";
  static const char * const zHasDupes = "\
SELECT count(DISTINCT (substring(name,1,nlen-chop)||suff) COLLATE NOCASE)\
 <count(name) FROM ColNames\
";
#ifdef SHELL_COLUMN_RENAME_CLEAN
  static const char * const zDedoctor = "\
UPDATE ColNames SET chop=iif(\
  (substring(name,nlen,1) BETWEEN '0' AND '9')\
  AND (rtrim(name,'0123456790') glob '*"AUTOCOLUMN_SEP"'),\
 nlen-length(rtrim(name, '"AUTOCOLUMN_SEP"0123456789')),\
 0\
)\
";
#endif
  static const char * const zSetReps = "\
UPDATE ColNames AS t SET reps=\
(SELECT count(*) FROM ColNames d \
 WHERE substring(t.name,1,t.nlen-t.chop)=substring(d.name,1,d.nlen-d.chop)\
 COLLATE NOCASE\
)\
";
#ifdef SQLITE_ENABLE_MATH_FUNCTIONS
  static const char * const zColDigits = "\
SELECT CAST(ceil(log(count(*)+0.5)) AS INT) FROM ColNames \
";
#else
  /* Counting on SQLITE_MAX_COLUMN < 100,000 here. (32767 is the hard limit.) */
  static const char * const zColDigits = "\
SELECT CASE WHEN (nc < 10) THEN 1 WHEN (nc < 100) THEN 2 \
 WHEN (nc < 1000) THEN 3 WHEN (nc < 10000) THEN 4 \
 ELSE 5 FROM (SELECT count(*) AS nc FROM ColNames) \
";
#endif
  static const char * const zRenameRank =
#ifdef SHELL_COLUMN_RENAME_CLEAN
    "UPDATE ColNames AS t SET suff="
    "iif(reps>1, printf('%c%0*d', '"AUTOCOLUMN_SEP"', $1, cpos), '')"
#else /* ...RENAME_MINIMAL_ONE_PASS */
"WITH Lzn(nlz) AS (" /* Find minimum extraneous leading 0's for uniqueness */
"  SELECT 0 AS nlz"
"  UNION"
"  SELECT nlz+1 AS nlz FROM Lzn"