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Overview
Comment:In the nextchar.c extension, allow the second argument to the next_char() function to be a subquery.
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SHA1: 59b9fa223681a7329533b350be7bf5a0a3609255
User & Date: drh 2013-09-28 13:28:40.044
Context
2013-09-28
16:43
Add new test file fts3defer3.test. (check-in: a6cd14effe user: dan tags: trunk)
13:28
In the nextchar.c extension, allow the second argument to the next_char() function to be a subquery. (check-in: 59b9fa2236 user: drh tags: trunk)
12:40
Updates to the sqlite3_analyzer utility: Change the names of some labels, especially change "Fragmentation" to "Non-sequential pages". Revise the computation of non-sequential pages so that it ignores itercalated non-leaf pages (overflow and index pages). (check-in: 3e5c7771fa user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to ext/misc/nextchar.c.
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** Further suppose that for user keypad entry, it is desired to disable
** (gray out) keys that are not valid as the next character.  If the
** the user has previously entered (say) 'cha' then to find all allowed
** next characters (and thereby determine when keys should not be grayed
** out) run the following query:
**
**   SELECT next_char('cha','dictionary','word');













*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** A structure to hold context of the next_char() computation across








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** Further suppose that for user keypad entry, it is desired to disable
** (gray out) keys that are not valid as the next character.  If the
** the user has previously entered (say) 'cha' then to find all allowed
** next characters (and thereby determine when keys should not be grayed
** out) run the following query:
**
**   SELECT next_char('cha','dictionary','word');
**
** IMPLEMENTATION NOTES:
**
** The next_char function is implemented using recursive SQL that makes
** use of the table name and column name as part of a query.  If either
** the table name or column name are keywords or contain special characters,
** then they should be escaped.  For example:
**
**   SELECT next_char('cha','[dictionary]','[word]');
**
** This also means that the table name can be a subquery:
**
**   SELECT next_char('cha','(SELECCT word AS w FROM dictionary)','w');
*/
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
#include <string.h>

/*
** A structure to hold context of the next_char() computation across
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      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
      return;
    }
  }else{
    zColl = "";
  }
  zSql = sqlite3_mprintf(
    "SELECT \"%w\" FROM \"%w\""
    " WHERE \"%w\">=(?1 || ?2) %s"
    "   AND \"%w\"<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
    "   %s"
    " ORDER BY 1 %s ASC LIMIT 1",
    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
  );
  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
  if( zColl[0] ) sqlite3_free(zColl);
  if( zSql==0 ){








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      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
      return;
    }
  }else{
    zColl = "";
  }
  zSql = sqlite3_mprintf(
    "SELECT %s FROM %s"
    " WHERE %s>=(?1 || ?2) %s"
    "   AND %s<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
    "   %s"
    " ORDER BY 1 %s ASC LIMIT 1",
    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
  );
  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
  if( zColl[0] ) sqlite3_free(zColl);
  if( zSql==0 ){
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Changes to test/spellfix.test.
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    CREATE TABLE vocab(w TEXT PRIMARY KEY);
    INSERT INTO vocab SELECT word FROM t1;
  }
} {}
do_execsql_test 1.11 {
  SELECT next_char('re','vocab','w');
} {a}



do_execsql_test 1.12 {
  SELECT next_char('r','vocab','w');
} {ae}
do_execsql_test 1.13 {
  SELECT next_char('','vocab','w');
} {r}
do_test 1.14 {








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    CREATE TABLE vocab(w TEXT PRIMARY KEY);
    INSERT INTO vocab SELECT word FROM t1;
  }
} {}
do_execsql_test 1.11 {
  SELECT next_char('re','vocab','w');
} {a}
do_execsql_test 1.11sub {
  SELECT next_char('re','(SELECT w AS x FROM vocab)','x');
} {a}
do_execsql_test 1.12 {
  SELECT next_char('r','vocab','w');
} {ae}
do_execsql_test 1.13 {
  SELECT next_char('','vocab','w');
} {r}
do_test 1.14 {
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