Moodle 3.2 PostgreSQL 12 Error reading from database
Moodle 3.2 site started showing error “Error reading from database”.
I checked config.php, the database credentials are correct, i was able to login to Amazon AWS RDS PostgreSQL database with the credentaials and able to see the database tables with command \dt.
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psql -h mydb.hwfckmarrpeo.ap-southeast-2.rds.amazonaws.com -p 5432 -U moodle_user -W |
I enabled debug in DB with following SQL commands
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select * from mdl_config WHERE name = 'debug'; select * from mdl_config WHERE name = 'debugdisplay'; UPDATE mdl_config SET VALUE = 2047 WHERE name = 'debug'; UPDATE mdl_config SET VALUE = 1 WHERE name = 'debugdisplay'; |
But for some reason, moodle did not show any further debug info.
I did a search for the error message “Error reading from database” using ack command, that search inside files.
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root@ip-172-31-13-4:/var/www/html# ack "Error reading from database" lang/en/error.php 216:$string['dmlreadexception'] = 'Error reading from database'; root@ip-172-31-13-4:/var/www/html# ack dmlreadexception lib/dmllib.php 140: parent::__construct('dmlreadexception', NULL, $errorinfo); course/tests/externallib_test.php 1788: $this->assertEquals('dmlreadexception', $e->errorcode); lang/en/error.php 216:$string['dmlreadexception'] = 'Error reading from database'; root@ip-172-31-13-4:/var/www/html# |
I added some debug code in file
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lib/dmllib.php |
That shows the SQL command that caused the failure. The error was
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ERROR: column d.adsrc does not exist |
This was because PostgreSQL removed the column name adsrc. To fix, edit file
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vi /var/www/html/lib/dml/pgsql_native_moodle_database.php |
Find (On line 394)
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$sql = "SELECT a.attnum, a.attname AS field, t.typname AS type, a.attlen, a.atttypmod, a.attnotnull, a.atthasdef, d.adsrc |
Replace with
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$sql = "SELECT a.attnum, a.attname AS field, t.typname AS type, a.attlen, a.atttypmod, a.attnotnull, a.atthasdef, pg_get_expr(d.adbin::pg_node_tree, d.adrelid) AS adsrc |
For more information on this patch, see MDL-67220
See moodle
Many thanks, this did the trick!
This got me out of trouble with a PostreSQL upgrade on Moodle 3.5, thanks.
This solution was really helpful. Thank you soo much.