问题
I have php-script running on top of apache. Every time when user goes to specific URL, he/she will get csv-file.
Column names are fetched like this (thanks to Daniel Figueroa :)
$csv_output .= "\n";
// get the column name from the first DB (ins.data)
mysql_select_db($db, $link) or die("Can not connect to DB1.");
$result = mysql_query("SHOW COLUMNS FROM ".$table." WHERE Field NOT IN
('ID','Key','Text')");
$i = 0;
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
$csv_output .= $row['Field']."; ";
$i++;
}
}
// get the column names from the second DB (Cu.data)
mysql_select_db($db2, $link) or die("Can not connect to DB2.");
$result = mysql_query("SHOW COLUMNS FROM ".$table2." ");
;
$i = 0;
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
$csv_output .= $row['Field']."; ";
$i++;
}
}
$csv_output .= "\n";
Actual query on PHP-script goes like this:
$values = mysql_query(" SELECT ins.data.`Date`, ins.data.`Number`,
ins.data.`Email`, ins.data.`TargetId`, ins.data.`CSW`,
ins.data.`TSW`, ins.data.`CType`,
Cu.data.`Cus`, Cu.data.`Co`,Cu.data.`Ci`,
Cu.data.`SID`, Cu.data.`SType`
FROM ins.data
LEFT JOIN Cu.data ON (ins.data.TargetId = Cu.data.TargetID)
ORDER BY ins.data.ID DESC");
Output of 'desc':
mysql> desc ins.data;
+-------------------+------------------+------+-----+---------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+------------------+------+-----+---------------------+----------------+
| ID | int(10) unsigned | NO | PRI | NULL | auto_increment |
| Date | timestamp | NO | | 0000-00-00 00:00:00 | |
| Number | text | NO | | NULL | |
| Text | text | NO | | NULL | |
| Email | text | NO | | NULL | |
| TargetId | varchar(20) | NO | | NULL | |
| CSW | text | NO | | NULL | |
| TSW | text | NO | | NULL | |
| Key | text | NO | | NULL | |
| CType | text | NO | | NULL | |
+-------------------+------------------+------+-----+---------------------+----------------+
10 rows in set (0.00 sec)
mysql> desc Cu.data;
+----------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+---------------+------+-----+---------+-------+
| Title | decimal(15,0) | NO | | NULL | |
| Cu | text | NO | | NULL | |
| Co | text | NO | | NULL | |
| Ci | text | NO | | NULL | |
| SID | text | NO | | NULL | |
| TargetID | varchar(20) | NO | MUL | NULL | |
| SType | text | NO | | NULL | |
| empty1 | int(11) | NO | | NULL | |
| empty2 | int(11) | NO | | NULL | |
| empty3 | int(11) | NO | | NULL | |
| empty4 | int(11) | NO | | NULL | |
| empty5 | int(11) | NO | | NULL | |
| empty6 | int(11) | NO | | NULL | |
| empty7 | int(11) | NO | | NULL | |
+----------+---------------+------+-----+---------+-------+
12 rows in set (0.00 sec)
UPDATE 3:
This is no more NATURAL LEFT JOIN-issue. Replaced with LEFT JOIN.
Added fields empty1-5 to ins.data to get data to csv-file. Without fields empty1-5, only data from first db (ins.data) was on csv.file.
Now i have data on all fields but field (or column names on excel) names on csv are on wrong order and not wanted fields (columns) are visible like Title and empty1-5.
Any ideas how to fix this? Some other way to get Field names to csv-file without "SHOW COLUMNS"?
I could write with 'echo' in the beginning of csv-file values what i want. ie "Date; Number; Email; TargetID, CSW; TSW; CType; Cu; SID; Co; Ci; SType;" but i am so newbie with PHP that i don't know how :(
Another issue is that if field ID is first column on excel, excel cannot handle that and it must be excluded from SHOW COLUMNS output.
UPDATE4: Added more empty-fields to DB2 (Cu.data) and reordered SQL-query, now all values are visible and on right order.
回答1:
EDIT
First of all, your table naming schema is weird and unusual... but assuming I understand it correctly then this query should work (if it does not then rename your tables without the dots (periods) to make things less confusing:
mysql_query('SELECT ins.data.Date, ins.data.Number, ins.data.Email, ins.data.TID, ins.data.CSW, ins.data.TSW, ins.data.CType, CU.data.SID, cu.data.SType, cu.data.CU, cu.data.CO, cu.data.Ci, FROM ins.data, cu.data ORDER BY ins.data.ID DESC');
According to to the mysql_query function reference, data should not end with a semicolon when using mysql_query in PHP... i never put the semicolon in there so I don't ever have a problem, that's what I initially noticed with your script (as I said i've never tried it so I don't know if thats the issue). Should be:
$values = mysql_query("SELECT Date, Number, Email, TID, CSW, TSW, CType, SID, SType, Cu, Co, Ci FROM ins.data NATURAL LEFT JOIN Cu.data ORDER BY ID DESC");
Also, when doing JOINS, usually you specify what column belongs to what table... like in the standard mysql example here:
<?php
// Make a MySQL Connection
// Construct our join query
$query = "SELECT family.Position, food.Meal ".
"FROM family LEFT JOIN food ".
"ON family.Position = food.Position";
$result = mysql_query($query) or die(mysql_error());
// Print out the contents of each row into a table
while($row = mysql_fetch_array($result)){
echo $row['Position']. " - ". $row['Meal'];
echo "<br />";
}
?>
I don't always use the JOIN commands either... you can use an alternative syntax like so:
mysql_query('SELECT ... FROM t1, t2, t3 WHERE t1.b = t2.b AND t2.c = t3.c AND t1.a = t3.a');
回答2:
Try putting aliases on table names. It will make the query more readable, too:
SELECT
i.`Date`, i.Number, i.Email, i.TID, i.CSW, i.TSW, i.CType,
c.Cu, c.Co, c.Ci, c.SID, c.TID, c.SType
FROM
ins.data AS i
LEFT JOIN
Cu.data AS c
ON i.TID = c.TID
ORDER BY
i.ID DESC ;
来源：https://stackoverflow.com/questions/11895724/php-mysql-left-join-output