Is there a practical reason why eval.c was designed with only two parameters?
https://www.sqlite.org/src/artifact/f971962e92ebb8b0 Why eval(X,Y) instead of eval(X,Y,Z)? The second form with both an optional column separator Y and an optional row separator Z is far more useful. I develop an interesting test case below. Using the proposed extension function eval3(X,Y,Z) in native SQLite, I compute a persistent db meta-data table 'columns' by aggregating the output of PRAGMA table_info() over the system table. Connected to a transient in-memory database. Use ".open FILENAME" to reopen on a persistent database. sqlite> sqlite> --table meta data experiments sqlite> .load sqlite-ext/eval3 sqlite> .load sqlite-ext/csv sqlite> sqlite> DROP VIEW IF EXISTS columns_refresh; sqlite> CREATE VIEW IF NOT EXISTS columns_refresh AS SELECT (null)refresh; sqlite> DROP TRIGGER IF EXISTS columns_refresh; sqlite> CREATE TRIGGER IF NOT EXISTS columns_refresh INSTEAD OF INSERT ON columns_refresh BEGIN ...> SELECT eval3('DROP TABLE IF EXISTS columns'); ...> WITH columns_csv_str AS ...> (SELECT group_concat(eval3(printf('pragma table_info(''%s'')',name),',',','||name||char(10)),'')str FROM sqlite_master WHERE type='table') ...> SELECT eval3(printf( ...> 'CREATE VIRTUAL TABLE columns USING csv(data=''%s'',schema=''CREATE TABLE x(cid,name,type,not_null,dflt_value,pk,tableName)'')' ...> ,str)) FROM columns_csv_str; ...> END; sqlite> .header on sqlite> SELECT * FROM columns; Error: no such table: columns sqlite> CREATE TABLE artist( ...> artistid INTEGER PRIMARY KEY, ...> artistname TEXT ...> ); sqlite> INSERT INTO columns_refresh VALUES(1); sqlite> SELECT * FROM columns; cid|name|type|not_null|dflt_value|pk|tableName 0|artistid|INTEGER|0||1|artist 1|artistname|TEXT|0||0|artist sqlite> CREATE TABLE track( ...> trackid INTEGER, ...> trackname TEXT, ...> trackartist INTEGER, ...> FOREIGN KEY(trackartist) REFERENCES artist(artistid) ...> ); sqlite> INSERT INTO columns_refresh VALUES(1); sqlite> SELECT * FROM columns; cid|name|type|not_null|dflt_value|pk|tableName 0|artistid|INTEGER|0||1|artist 1|artistname|TEXT|0||0|artist 0|trackid|INTEGER|0||0|track 1|trackname|TEXT|0||0|track 2|trackartist|INTEGER|0||0|track sqlite> SELECT (tableName||'.'||name)int_cols FROM columns WHERE type LIKE 'INT%'; int_cols artist.artistid track.trackid track.trackartist sqlite> _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
