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Overview
Comment:Update the FTS3 documentation to make it clearer that external content tables must be in the same database as the FTS virtual table.
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SHA1: 35441559aa477c9f68d06127ed1c230e201c4557
User & Date: drh 2013-04-25 11:35:55
Context
2013-04-26
14:38
Add documentation for the fts3tokenize table. check-in: a6e655aa62 user: drh tags: trunk
2013-04-25
11:35
Update the FTS3 documentation to make it clearer that external content tables must be in the same database as the FTS virtual table. check-in: 35441559aa user: drh tags: trunk
2013-04-24
22:09
If the website keyword search fails, try again after lowercasing the input text. This avoids problems when users enter "OR" and "NEAR" as search terms rather than operators. check-in: 78cbbe549b user: drh tags: trunk
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Changes to pages/fts3.in.

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<codeblock>
  CREATE TABLE t2(id INTEGER PRIMARY KEY, a, b, c);
  CREATE VIRTUAL TABLE t3 USING fts4(content="t2", a, c);
</codeblock>

<p>
  Assuming the nominated table does exist, then its columns must be the same 
  as or a superset of those defined for the FTS table.





<p>
  When a users query on the FTS table requires a column value other than
  docid, FTS attempts to read this value from the corresponding column of
  the row in the content table with a rowid value equal to the current FTS
  docid. Or, if such a row cannot be found in the content table, a NULL
  value is used instead. For example:

<codeblock>
  CREATE TABLE t2(id INTEGER PRIMARY KEY, a, b, c, d);
  CREATE VIRTUAL TABLE t3 USING fts4(content="t2", b, c);







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<codeblock>
  CREATE TABLE t2(id INTEGER PRIMARY KEY, a, b, c);
  CREATE VIRTUAL TABLE t3 USING fts4(content="t2", a, c);
</codeblock>

<p>
  Assuming the nominated table does exist, then its columns must be the same 
  as or a superset of those defined for the FTS table.  The external table
  must also be in the same database file as the FTS table.  In other words,
  The external table cannot be in a different database file connected using
  [ATTACH] nor may one of the FTS table and the external content be in the
  TEMP database when the other is in a persistent database file such as MAIN.

<p>
  When a users query on the FTS table requires a column value other than
  docid, FTS attempts to read the requested value from the corresponding column of
  the row in the content table with a rowid value equal to the current FTS
  docid. Or, if such a row cannot be found in the content table, a NULL
  value is used instead. For example:

<codeblock>
  CREATE TABLE t2(id INTEGER PRIMARY KEY, a, b, c, d);
  CREATE VIRTUAL TABLE t3 USING fts4(content="t2", b, c);