I've got two databases on the same server. The Google gave me some hints but there wasn't anything "official" that I could find. Could someone point me to the documentation that explains how to do this? An explanation using PHP would be useful as well. Thanks!
I've got two databases on the same server. ...How do I construct a cross database query in MySQL?
You access other databases on the same MySQL instance by prefixing the table with the appropriate database name. IE:
SELECT *
FROM this_database.table_1 t1
JOIN that_database.table_2 t2 ON t2.column = t1.column
Keep in mind
A query executes with the credentials of the authentication used to set up the
connection. If you want to query two tables simultaneously across two (or more)
databases, the user used to run the query will need SELECT access to all
databases involved.
Reference:
Identity Qualifiers
SELECT * FROM DB1.myTable1 AS db1, DB2.myTable2 AS db2
http://www.dottedidesign.com/node/14 provides the following example:
SELECT
arbogast.node.nid as anid,
mcguffin.node.nid as mnid,
arbogast.node.title as atitle,
mcguffin.node.title as mtitle
FROM arbogast.node, mcguffin.node
WHERE arbogast.node.nid = 1
AND mcguffin.node.nid = arbogast.node.nid;
Where arbogast and mcguffin are different databases.
Related
have a series of databases on the same server which i am wishing to query. I am using the same code to query the database and would like the results to appear in a single list.
I am using 'USE' to specify which database to query, followed by creating some temporary tables to group my data, before using a final SELECT statement to bring together all the data from the database.
I am then using UNION, followed by a second USE command for the next database and so on.
SQL Server is showing a syntax error on the word 'UNION' but does not give any assistance as to the source of the problem.
Is it possible that I am missing a character. At present I am not using ( or ) anywhere.
The USE statement just redirects your session to connect to a different database on the same instance, you don't actually need to switch from database to database in this matter (there are a few rare exceptions tho).
Use the 3 part notation to join your result sets. You can do this while being connected to any database.
SELECT
SomeColumn = T.SomeColumn
FROM
FirstDatabase.Schema.TableName AS T
UNION ALL
SELECT
SomeColumn = T.SomeColumn
FROM
SecondDatabase.Schema.YetAnotherTable AS T
The engine will automatically check for your login's users on each database and validate your permissions on the underlying tables or views.
UNION adds result sets together, you can't issue another operation (like USE) other than SELECT between UNION.
You should use the database names before the table name:
SELECT valueFromBase1
FROM `database1`.`table1`
WHERE ...
UNION
SELECT valueFromBase2
FROM `database2`.`table2`
WHERE ...
In my SQL script I am using one database(Lets assume MyDb1).
In side that script I need to query extended property of another DB (MyDb2).
I have no Idea to do this.
Please advise me.
You can use this Query :
SELECT * FROM MyDb1.DBO.TableName as tbl1,MyDb2.DBO.TableName as tbl2
WHERE tbl1.ID=tbl2.ID
perl 5.10
Access 2010
SqlServer 2008 R2
So I need to update a column in table A with data in table B where A and B have a column I can JOIN on.
This would work great
$sqlCmd = "UPDATE aa SET aa.foo = bb.fancyfoo " .
"FROM [dbo.serverOne] AS aa " .
"RIGHT JOIN [noteTable] AS bb " .
"ON aa.[recid] = bb.[recid] " ;
$sth = $dbh->prepare( $sqlCmd);
IF both tables were in the same database since there's only one database handle in play.
But my tables reside on different databases , and in fact in different servers -- dbo.ServerOne lives in an instance of SqlServer while noteTable resides in an Access database ( sorry ).
And for extra added spice, bb.fancyfoo is defined as a MEMO and aa.foo is defined as a nvarchar(max)
Frankly I can't see how this can be achieved in one pass - can a sql command make use of more than one db handle?
If not , and I have to use two separate commands ie an UPDATE on dbo.ServerOne and SELECT on noteTable, how do I set this up to work for MEMO/nvarchar(max) fields? I mean, how should I store the data while its in beteween tables? CLOB?
TIA,
Still-learning Steve
Your luck is in - both tables can be in the same database.
What you need to google for is "linked tables". There is a brief overview here but basically it lets you add an external table via ODBC (or other supported connection method).
You can either link the Access table in to the SQL Server DB or the other way around. Which will depend on whether the Access file is in a fixed location and where the majority of your data is. It's probably more efficient to link to the smaller from the larger.
Having said that, I'd expect SQL Server to be smarter about planning/executing the query so I'd try that first.
Since we're already schlepping data out the the Access tables into SqlServer tables I decided to do the JOIN via adding fields from both tables to a hashref keyed on the shared key field. Not as elegant as I'd like, but it works.
Thanks to all who replied!
CASE CLOSED
Still-learning Steve
is there a way to actually query the database in a such a way to search for a particular value in every table across the whole database ?
Something like a file search in Eclipse, it searches accross the whole worspace and project ?
Sorry about that .. its MS SQL 2005
SQL Workbench/J has a built in tool and command to do that.
It's JDBC based and should also work with SQL Server.
You will need to use the LIKE operator, and search through each field separately. i.e.
SELECT * FROM <table name>
WHERE (<field name1> LIKE '%<search value>%') OR
(<field name2> LIKE '%<search value>%') OR
... etc.
This isn't a quick way though.
I think the best way would be to
1) programatically generate the query and run it
2) use a GUI tool for the SQL server you are using which provides this functionality.
In mysql you can use union operator like
(SELECT * from table A where name = 'abc') UNION (SELECT * from
table B where middlename = 'pqr')
and so on
use full text search for efficency
http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html
Well, your best bet is to write a procedure to do this. But to give you some pointers you can use the INFORMATION_SCHEMA.Tables to get a list of all the tables in a given database and INFORMATION_SCHEMA.Columns to get a list of all columns. These tables also give you the datatype of columns. So you will need a few loops on these tables to do the magic.
It should be mentioned most RDBMSs nowadays support these schemas.
In phpmyadmin, go to your database, reach the search tab.
Here you will be able to select all of your tables and search through your entire db in one time.
I'm trying to update all records in one table with the values found in another table.
I've tried many versions of the same basic query and always get the same error message:
Operation must use an updateable
query.
Any thoughts on why this query won't work in Access DB?
UPDATE inventoryDetails as idet
SET idet.itemDesc =
(
SELECT bomItemDesc
FROM BOM_TEMPLATES as bt
WHERE bt.bomModelNumber = idet.modelNumber
)
also tried this because I realized that since the second table has multiple model number records for each modelnumber - and I only need the first description from the first record found for each model number.
UPDATE inventoryDetails as idet
SET idet.item_desc =
(
SELECT TOP 1 bomItemDescription
FROM BOM_TEMPLATES as bt
WHERE bt.bomModelNumber = idet.modelNumber
)
...still getting the same error though.
You have to use a join
UPDATE inventoryDetails
INNER JOIN BOM_TEMPLATES ON inventoryDetails.modelNumber = BOM_TEMPLATES.bomModelNumber
SET inventoryDetails.itemDesc = [bomItemDesc];
Any thoughts on why this query won't work in Access DB?
The answer is, because ACE/Jet SQL syntax is not SQL-92 compliant (even when in its ANSI-92 Query Mode!).
I'm assuming yours is a scalar subquery. This construct is simply not supported by ACE/Jet.
ACE/Jet has its own quirky and flawed UPDATE..JOIN syntax, flawed because the engine doesn't force the JOINed values to be scalar and it is free to silently use an arbitrary value. It is different again from SQL Server's own UPDATE..JOIN syntax but at least SQL Server supports the Standard scalar subquery as an alternative. ACE/Jet forces you to either learn its quirky non-portable ways or to use an alternative SQL product.
Sorry to sound negative: the ACE/Jet engine is a great piece of software but UPDATE syntax is absolutely fundamental and the fact it hasn't been changed since the SQL-92 Standard really show its age.
try:
update idet
SET idet.itemDesc = bt.bomItemDesc
from inventoryDetails as idet
inner join BOM_TEMPLATES as bt
on bt.bomModelNumber = idet.modelNumber
This is how I would write it for SQL server. Hope Access understands the same command.