L-electron-Rare/moodle
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MDL-35155 database: better sql_substr() impl. for mssql/sqlsrv + unit tests

Browse Source 
MSSQL's substring() implementation is somehow silly/strict and unable to
perform implicit casts to integer both for the start and length parameters.

This hits Moodle badly because of another problems (MDL-23997) we decided
to cast to string all bound placeholders long ago.

So this commit just enforces the cast of the start and length parameters to
integer. And includes unit tests for using placeholders on all positions in
the sql_substr() method.
This commit is contained in:
Eloy Lafuente (stronk7)
2015-01-12 18:26:38 +01:00
parent 817f22818b
commit de12ede98e
3 changed files with 28 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/dml/mssql_native_moodle_database.php
+2 -2
View File
@@ -1257,9 +1257,9 @@ class mssql_native_moodle_database extends moodle_database {
s only returning name of SQL substring function, it now requires all parameters.');
}
if ($length === false) {
return "SUBSTRING($expr, $start, LEN($expr))";
return "SUBSTRING($expr, " . $this->sql_cast_char2int($start) . ", 2^31-1)";
} else {
return "SUBSTRING($expr, $start, $length)";
return "SUBSTRING($expr, " . $this->sql_cast_char2int($start) . ", " . $this->sql_cast_char2int($length) . ")";
}
}
lib/dml/sqlsrv_native_moodle_database.php
+2 -2
View File
@@ -1324,9 +1324,9 @@ class sqlsrv_native_moodle_database extends moodle_database {
}
if ($length === false) {
return "SUBSTRING($expr, $start, LEN($expr))";
return "SUBSTRING($expr, " . $this->sql_cast_char2int($start) . ", 2^31-1)";
} else {
return "SUBSTRING($expr, $start, $length)";
return "SUBSTRING($expr, " . $this->sql_cast_char2int($start) . ", " . $this->sql_cast_char2int($length) . ")";
}
}
lib/dml/tests/dml_test.php
+24 -3
View File
@@ -4027,9 +4027,30 @@ class core_dml_testcase extends database_driver_testcase {
$this->assertInstanceOf('coding_exception', $e);
}
$sql = "SELECT id, ".$DB->sql_substr("name", ":param1 + 1")." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => 4));
$this->assertEquals(substr($string, 5-1), $record->name);
// Cover the function using placeholders in all positions.
$start = 4;
$length = 2;
// 1st param (target).
$sql = "SELECT id, ".$DB->sql_substr(":param1", $start)." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => $string));
$this->assertEquals(substr($string, $start - 1), $record->name); // PHP's substr is 0-based.
// 2nd param (start).
$sql = "SELECT id, ".$DB->sql_substr("name", ":param1")." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => $start));
$this->assertEquals(substr($string, $start - 1), $record->name); // PHP's substr is 0-based.
// 3rd param (length).
$sql = "SELECT id, ".$DB->sql_substr("name", $start, ":param1")." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => $length));
$this->assertEquals(substr($string, $start - 1, $length), $record->name); // PHP's substr is 0-based.
// All together.
$sql = "SELECT id, ".$DB->sql_substr(":param1", ":param2", ":param3")." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => $string, 'param2' => $start, 'param3' => $length));
$this->assertEquals(substr($string, $start - 1, $length), $record->name); // PHP's substr is 0-based.
// Try also with some expression passed.
$sql = "SELECT id, ".$DB->sql_substr("name", "(:param1 + 1) - 1")." AS name FROM {{$tablename}}";
$record = $DB->get_record_sql($sql, array('param1' => $start));
$this->assertEquals(substr($string, $start - 1), $record->name); // PHP's substr is 0-based.
}
public function test_sql_length() {