I have MySQL 4.1 server version installed. I want to use the 'show query' as a subquery in a SELECT statement.
For example:
SELECT count(*) from (SHOW VARIABLES LIKE 'log_bin');
But this gives me an error like:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SHOW VARIABLES LIKE 'log_bin')' at line 1
As per my understanding and my research on web, I figured that 'show queries' can't be used as subqueries.
Well I came across the function called FOUND_ROWS(). But this function returns me 1 on any 'show query' I do. For example:
show tables; select FOUND_ROWS();
And gives me this:
+----------------------+
| Tables_in_test |
+----------------------+
| test1 |
| test2 |
+----------------------+
2 rows in set (0.00 sec)
+--------------+
| FOUND_ROWS() |
+--------------+
| 1 |
+--------------+
1 row in set (0.00 sec)
As I use MySQL 4.1, the information_schema database is not yet introduced. Is there any other way I could solve my issue?
Conditions:
I have to use MySQL 4.1
Should get count using MySQL queries.
You can use information schema
SELECT table_name FROM INFORMATION_SCHEMA.TABLES
WHERE table_schema = 'db_name'
[AND table_name LIKE 'urtable']
Related
I have the following columns in my dataset:
_____________________________________________________________________________________
| ... |Start Date| Start Time | End Date | End Time | Production Start Date | ... |
|_____|__________|____________|____________|____________|_______________________|_____|
| ... | 01022020 | 180000 | 02022020 | 190000 | 01022020 | ... |
| | | | | | | |
Sometimes the Start Date + Start Time etc. values are blank but the Production Start Date values are always populated.
When the Start Date is empty (NULL), for example, I want my dataset (or ideally, graph) to read the Production Start Date.
How can I achieve this in Power BI?
I know I can make a conditional column, then within that, determine which column to read data from but is there any way to add a condition to the existing Start Date column? I couldn't see such an option in the context menu or subsequent ribbon options.
Is my only option to create a custom conditional column instead?
As #Andrey Nikolov mentioned in the comments, the only ways you can achieve this is to:
1 Create a calculated DAX column.
2 Create a custom column in query mode (M).
3 Edit the original source table.
doug
I have a table that contains multiple columns with their named having either the suffix _EXPECTED or _ACTUAL. For example, I'm looking at my sold items from my SoldItems Table and I have the following columns: APPLES_EXPECTED, BANANAS_EXPECTED, KIWIS_EXPECTED, APPLES_ACTUAL, BANANAS_ACTUAL, KIWIS_ACTUAL (The Identifier of the table is the date, so we have results per date). I want to show that data in a table form, something like this (for a selected date in filters:
+------------+----------+--------+
| Sold items | Expected | Actual |
+------------+----------+--------+
| Apples | 10 | 15 |
| Bananas | 8 | 5 |
| Kiwis | 2 | 1 |
+------------+----------+--------+
How can I manage something like this in Power BI ? I tried playing with the matrix/table visualization, however, I can't figure out a way to merge all the expected and actual columns together.
It looks like the easiest option for you would be to mould the data a bit differently using Power query. You can UNPIVOT your data so that all the expected and actual values become rows instead of columns. For example take the following sample:
Date Apples_Expected Apples_Actual
1/1/2019 1 2
Once you unpivot this it will become:
Date Fruit Count
1/1/2019 Apples_Expected 1
1/1/2019 Apples_Actual 2
Once you unpivot, it should be fairly straightforward to get the view you are looking for. The following link should walk you through the steps to unpivot:
https://support.office.com/en-us/article/unpivot-columns-power-query-0f7bad4b-9ea1-49c1-9d95-f588221c7098
Hope this helps.
I have two tables like the fallowing:
On server:
| Orders Table | OrderDetails Table
-------------------------------------------------------------------------------------
| Id | Id
| OrderDate | OrderId
| ServerName | Product
| Quantity
On client:
| Orders Table | OrderDetails Table
-------------------------------------------------------------------------------------
| Id | Id
| OrderDate | OrderId
| Product
| Quantity
| ClientName
I need to sync the [Server].[Orders Table].[ServerName] to [Client].[OrderDetails Table].[ClientName]
The Question:
What is the true and efficient way of making it?
I know Deprovisioning and provisioning with different config, is one way of doing it.
So I just wanna know the correct way.
Thanks.
EDIT :
Other columns of each table should sync normally ([Server].[Orders Table].[Id] to [Client].[Orders Table].[Id] ...).
And mapping strategy sometimes changes based on the row of data (which which is sending/receiving).
Sync Fx is not an ETL tool. simply put, it's DB sync is per table.
if you really want to force it to do what you want, you can simply intercept ChangesSelected event for the OrderDetails table, lookup the extra column from the other table and then dynamically add the column to the dataset before it gets applied on the other side.
see this link on how to manipulate the change dataset
I have two tables in transformation and I need to get data from two tables which does not meet on common key. i.e I am doing join on table A and B
from table A I need those records which are not present in table B.
it will be helpful if someone can tell me what step I can use in Kettle spoon to do above transformation
You can achieve this with the Merge Join step. Under Join Type choose LEFT OUTER. After this step your results will look like this:
key_a|value_a|key_b|value_b
1 | 1| null | null
2 | 2 | null | null
3 | 3| 3| 3|
Then choose the Filter rows step and set key_b as the field and the condition to IS NULL.
If you also need records where key_a does not match key_b, choose the Join Type as FULL OUTER.
If both your tables are in a database of the same type, this can easily be achieved by using the Table input step and doing the join in the query itself:
SELECT table_a.key
, table_a.value
FROM table_a
LEFT JOIN table_b
ON table_a.key = table_b.key
WHERE table_b.key IS NULL
I am using MySQL and a prepared statement to insert a BLOB record (jpeg image). After executing the prepared statement, I issue a SELECT LAST_INSERT_ID() and it returns 0.
In my code I put a breakpoint after the execution command and in a MySQL command (monitor) window, I issue the SELECT LAST_INSERT_ID() and it returns zero.
In the MySQL command (monitor) window, I issue an SQL statement to select all the IDs and the last (only) inserted ID is 1 (one).
I am using:
Server version: 5.1.46-community
MySQL Community Server (GPL)
Visual Studio 2008, version 9.
MySQL Connector C++ 1.0.5
My table description:
mysql> describe picture_image_data;
+---------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+------------------+------+-----+---------+----------------+
| ID_Image_Data | int(10) unsigned | NO | PRI | NULL | auto_increment |
| Image_Data | mediumblob | YES | | NULL | |
+---------------+------------------+------+-----+---------+----------------+
2 rows in set (0.19 sec)
Results using MySQL monitor:
mysql> select ID_Image_Data
-> from picture_image_data;
+---------------+
| ID_Image_Data |
+---------------+
| 1 |
+---------------+
1 row in set (0.00 sec)
mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 0 |
+------------------+
1 row in set (0.00 sec)
The Prepared statement:
INSERT INTO Picture_Image_Data
(ID_Image_Data, Image_Data)
VALUES
(?,
?);
The results above show that the ID_Image_Data field is one, but the LAST_INSERT_ID is zero. The table is created before this statement is executed, so this is the only record in the table.
Edit:
I am setting the ID field to zero and the next field to a C++ std::istream *. According to the MySQL Manual Page for LAST_INSERT_ID():
The value of LAST_INSERT_ID() is not changed if you set the AUTO_INCREMENT column of a row to a non-“magic” value (that is, a value that is not NULL and not 0).
The LAST_INSERT_ID() should return 1 since the ID value in the prepared statement is 0.
Do I need to make a prepared statement for fetching LAST_INSERT_ID?
{Searching the web showed to use a custom MySQL API, but that used PHP and futher comments said it needs another connection).
LAST_INSERT_ID would only work for auto generated primary key, that was created on auto_increment field. In your case, it looks like you are supplying the id explicitly, so last insert id is not set.
This is explicit:
mysql> insert into test (id, name) VALUES (5, 'test 2');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 0 |
+------------------+
1 row in set (0.00 sec)
This is implicit:
mysql> insert into test (name) values ('test');
Query OK, 1 row affected (0.00 sec)
mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 3 |
+------------------+
1 row in set (0.00 sec)
Looks like the issues is with the MySQL C++ connector.
LAST_INSERT_ID() returns 0 when
the ID field is null, explicit
insert.
LAST_INSERT_ID() returns 0 when
the ID field is not specified,
implicit insert.
I tried insert the BLOB (JPEG image) from the command line (monitor), and it works:
mysql> describe picture_image_data;
+---------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+------------------+------+-----+---------+----------------+
| ID_Image_Data | int(10) unsigned | NO | PRI | NULL | auto_increment |
| Image_Data | mediumblob | YES | | NULL | |
+---------------+------------------+------+-----+---------+----------------+
2 rows in set (0.03 sec)
mysql> PREPARE blob_stmt
-> FROM 'INSERT INTO picture_image_data (ID_Image_Data, Image_Data) VALUES (?, LOAD_FILE(?))';
Query OK, 0 rows affected (0.02 sec)
Statement prepared
mysql> SET #id = 0;
Query OK, 0 rows affected (0.00 sec)
mysql> SET #c = 'KY_hot_brown_picture.jpg';
Query OK, 0 rows affected (0.00 sec)
mysql> EXECUTE blob_stmt USING #id, #c;
Query OK, 1 row affected (0.15 sec)
mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 2 |
+------------------+
1 row in set (0.00 sec)
For now, the workaround is to use SQL statements to insert the BLOB with a prepared statement rather than the MySQL C++ Connector API.
You cannot expect issuing a SELECT LAST_INSERT_ID() on the mysql command line client to give you the last inserted value that was generated in your C++ code.
LAST_INSERT_ID() gives you the last autogenerated ID on the given connection. Obviously your C++ program and the mysql client uses 2 different connections to the mysql server.
(and LAST_INSERT_ID() should be used after an INSERT too, don't have other SQL statements inbetwwen the INSERT and SELECTLAST_INSERT_ID())