I need to run following query in my stored function with variables
SELECT json_unquote(json_extract(value,'$."_key"')) INTO org_rank_value FROM preferences WHERE id=_id;
Here _key and _id are declared variables, but _key is not replaced with value since it is in quotes. Is there any way to build and execute above query?
Without more context about your database structure, this is how i interpreted your question.
1) you want to select a specific ID.
2) you want to change a parameter within your json-field based off of the ID.
3) you want to execute the query.
DECLARE #json NVARCHAR(MAX) = (SELECT org_rank_value FROM preferences WHERE id=_id)
SELECT * FROM OPENJSON(#json)
WITH (
yourKey varchar(200) '$.key' -- change to whatever your variables are.
) AS changeKey;
UPDATE preferences SET json_unquote(json_extract(value,'$."_key"')) INTO org_rank_value WHERE id=_id;
In MySQL, u can use
JSON_ARRAY_APPEND
Related
I am trying to write a function that looks for a value assigned to its configuration in a parent-child tree, if the value is null or empty it looks one level up for the value.
I am currently getting syntax errors when trying to create the function.
This is what i have so far,
DELIMITER //
CREATE FUNCTION `db`.`Configuration`(
`ColumnName` VARCHAR(128),
`CID` INT
)
RETURNS VARCHAR(256)
NOT DETERMINISTIC
BEGIN
DECLARE Config VARCHAR(256) DEFAULT NULL;
DECLARE Parent INT;
WHILE (#Config IS NULL OR #Config = "") DO
SELECT #ColumnName INTO #Config, `ParentID` INTO #Parent FROM `Table` WHERE `ID`=#CID;
END WHILE;
RETURN CONCAT(#Config, '::', #Parent);
END ;
//
DELIMITER ;
I am getting the following error when I try to add the function:
1327 - Undeclared variable: ParentID
Any help would be greatly appreciated!
You receive the error message in the question because you have multiple into clauses, whereas according to mysql manual on select ... into ... you can only have one. So, to get rid of this specific error message you nee to rewrite your select statement as:
SELECT #ColumnName, `ParentID` INTO #Config, #Parent FROM `Table` WHERE `ID`=#CID;
However, there are some further issues with your code:
varname and #varname do not refer to the same variable. The first one is either a function / stored proc parameter or local variable, while the 2nd one is a user-defined variable. In your code you must remove the # from the variable names.
You cannot use a variable in place of a field name in an sql statement. You must use dynamic sql with prepared statements to achieve this. See the following SO question on how to this: How To have Dynamic SQL in MySQL Stored Procedure
You do not overwrite CID parameter in your while loop. This means that if the first iteration the configuration will remain null, then you have an infinite loop. You should change the value of CID in your loop.
I cannot guarantee that there are no further errors in your code.
There are a few problems with your function:
You are using SELECT...INTO incorrectly. When selecting multiple values you should only use INTO once. For example SELECT a,b into #a,#b FROM...
You are using user-defined variables with similar names to your function parameters, but they are not the same thing. In your code CID and #CID are different. I suggest using standard naming prefixes to clarify this: for example use p_ for function parameters and v_ for local function variables. You shouldn't need to use user-defined variables at all.
Your WHILE loop is bound to lead to infinite loops since the query criteria never changes. If it returns NULL or empty string once, it will keep returning them forever.
Here's a quick rewrite to address the above issues. I'll leave it to you to implement the WHILE loop correctly:
DELIMITER //
CREATE FUNCTION `db`.`Configuration`(
p_column_name VARCHAR(128),
p_id INT
)
RETURNS VARCHAR(256)
READS SQL DATA
BEGIN
DECLARE v_config VARCHAR(256) DEFAULT NULL;
DECLARE v_parent INT;
SELECT p_column_name,`ParentID`
INTO v_config, v_parent
FROM `Table`
WHERE `ID`=p_id;
RETURN CONCAT(v_config, '::', v_parent);
END ;
//
DELIMITER ;
I have the following stored procedure in a MYSQL database. The stored procedure gets lon,lat and than I'm doing an update on a different database and table.
DROP PROCEDURE IF EXISTS annuals.updateSalesFlorida;
CREATE DEFINER=`dddd`#`%` PROCEDURE `updateSales`(propertyId int)
BEGIN
DECLARE lat FLOAT;
DECLARE lon FLOAT;
SELECT SitusLongitude,SitusLatitude
INTO lon,lat
FROM annuals.florida
WHERE PropertyID=propertyId
LIMIT 1 FOR UPDATE;
UPDATE sales.florida
SET
`SitusLongitude` = lon,
`SitusLatitude` = lat
WHERE PROPERTYUNIQUEID=propertyId;
END;
Every time I run the stored procedure the SitusLongitude and SitusLatitude columns are 0. I know for a fact that the previous selected SitusLongitude and SitusLatitude have actual values in there. For some reason the variables are not being set in lat,lon. Any idea what I'm dong wrong?
The problem is that the procedure parameter has the same name as a column in the tables. When you refer to propertyid in the queries, it uses the column, not the parameter. Column and variable names are case-insensitive, so it doesn't matter that you spelled one of them PropertyID and the other propertyId.
Use a different name for the parameter, e.g. p_propertyId
Also, there's no need for two queries, you can do it in one with a JOIN.
UPDATE sales.florida AS s
CROSS JOIN (
SELECT *
FROM annuals.florida
WHERE propertyId = p_propertyId
LIMIT 1) AS a
SET s.SitusLongitude = a.SitusLongitude, s.SitusLatitude = a.SitusLatitude
WHERE s.PROPERTYUNIQUEID = p_propertyId
Note that using LIMIT without ORDER BY means that the row that's selected will be unpredictable.
Let's say a have a stored procedure SetCustomerName which has an input parameter Name, and I have a table customers with column Name.
So inside my stored procedure I want to set customer's name. If I write
UPDATE customers SET Name = Name;
this is incorrect and I see 2 other ways:
UPDATE customers SET Name = `Name`;
UPDATE customers SET customers.Name = Name;
First one works, but I didn't find in documentation that I can wrap parameters inside ` characters. Or did I miss it in the documentation (link is appreciated in this case).
What other ways are there and what is the standard way for such a case? Renaming input parameter is not good for me (because I have automatic object-relational mapping if you know what I mean).
UPDATE:
So, there is a link about backticks (http://dev.mysql.com/doc/refman/5.0/en/identifiers.html) but it's not explained deep enough how to use them (how to use them with parameters and column names).
And there is a very strange thing (at least for me): You can use backticks either way:
UPDATE customers SET Name = `Name`;
//or
UPDATE customers SET `Name` = Name;
//or even
UPDATE customers SET `Name` = `Name`;
and they all work absolutely the same way.
Don't you think this is strange? Is this strange behavior explained somewhere?
Simplest way to distinguished between your parameter and column (if both name is same) is to add table name in your column name.
UPDATE customers SET customers.Name = Name;
Even you can also add database prefix like
UPDATE yourdb.customers SET yourdb.customers.Name = Name;
By adding database name you can perform action on more than 1 database from single store procedure.
I think that your first example is actually backwards. If you're trying to set the "Name" column to the "Name" input parameter, I believe it should be:
UPDATE customers SET `Name` = Name;
And for the second example, you can set table aliases the same way that you do in all other statements:
UPDATE customers AS c SET c.Name = Name;
Not necessarily correct, but a fair way to better argument/parameter management, as well readability with easier understanding, especially while working with the SQL;
DROP PROCEDURE IF EXISTS spTerminalDataDailyStatistics; DELIMITER $$
CREATE PROCEDURE spTerminalDataDailyStatistics(
IN TimeFrom DATETIME,
IN DayCount INT(10),
IN CustomerID BIGINT(20)
) COMMENT 'Daily Terminal data statistics in a date range' BEGIN
# Validate argument
SET #TimeFrom := IF(TimeFrom IS NULL, DATE_FORMAT(NOW(), '%Y-%m-01 00:00:00'), TimeFrom);
SET #DayCount := IF(DayCount IS NULL, 5, DayCount);
SET #CustomerID := CustomerID;
# Determine parameter
SET #TimeTo = DATE_ADD(DATE_ADD(#TimeFrom, INTERVAL #DayCount DAY), INTERVAL -1 SECOND);
# Do the job
SELECT DATE_FORMAT(TD.TerminalDataTime, '%Y-%m-%d') AS DataPeriod,
COUNT(0) AS DataCount,
MIN(TD.TerminalDataTime) AS Earliest,
MAX(TD.TerminalDataTime) AS Latest
FROM pnl_terminaldata AS TD
WHERE TD.TerminalDataTime BETWEEN #TimeFrom AND #TimeTo
AND (#CustomerID IS NULL OR TD.CustomerID = #CustomerID)
GROUP BY DataPeriod
ORDER BY DataPeriod ASC;
END $$
DELIMITER ;
CALL spTerminalDataDailyStatistics('2021-12-01', 2, 1801);
Using backticks in MySQL query syntax is documented here:
http://dev.mysql.com/doc/refman/5.0/en/identifiers.html
So yes, your first example (using backticks) is correct.
Here is the link you are asking for:
http://dev.mysql.com/doc/refman/5.0/en/identifiers.html
The backticks are called "identifier quote" in MySql
I tried setting a variable in sql as follows:
DECLARE #fromDate VARCHAR(60);
SET #fromDate = '2013-01-01 00:00:00';
SET #toDate = '2013-02-01 00:00:00';
SELECT #fromDate;
but this is not working.
what am I doing incorrectly?
You don't DECLARE variables that start with #.
MySQL has two different types of variables. One is a session variable, with the # prefix. The other type is the local variable inside a trigger or stored proc.
The DECLARE statement is valid only inside of body of stored procedure or function, and this variables don't start by #.
The variables that start with # don't need DECLARE, just use outside of stored procedure inclusive.
First lets take a look at how can we define a variable in mysql
To define a varible in mysql it should start with '#' like #{variable_name} and this '{variable_name}', we can replace it with our variable name.
Now, how to assign a value in a variable in mysql. For this we have many ways to do that
Using keyword 'SET'.
Example :- mysql > SET #a = 1;
Without using keyword 'SET' and using ':='.
Example:- mysql > #a:=1;
By using 'SELECT' statement.
Example:- mysql > select 1 into #a;
Here #a is user defined variable and 1 is going to be assigned in #a.
Now how to get or select the value of #{variable_name}.
we can use select statement like
Example :-
mysql > select #a;
it will show the output and show the value of #a.
Now how to assign a value from a table in a variable.
For this we can use two statement like :-
#a := (select emp_name from employee where emp_id = 1);
select emp_name into #a from employee where emp_id = 1;
Always be careful emp_name must return single value otherwise it will throw you a error in this type statements.
refer this:- http://www.easysolutionweb.com/sql-pl-sql/how-to-assign-a-value-in-a-variable-in-mysql
Let's say a have a stored procedure SetCustomerName which has an input parameter Name, and I have a table customers with column Name.
So inside my stored procedure I want to set customer's name. If I write
UPDATE customers SET Name = Name;
this is incorrect and I see 2 other ways:
UPDATE customers SET Name = `Name`;
UPDATE customers SET customers.Name = Name;
First one works, but I didn't find in documentation that I can wrap parameters inside ` characters. Or did I miss it in the documentation (link is appreciated in this case).
What other ways are there and what is the standard way for such a case? Renaming input parameter is not good for me (because I have automatic object-relational mapping if you know what I mean).
UPDATE:
So, there is a link about backticks (http://dev.mysql.com/doc/refman/5.0/en/identifiers.html) but it's not explained deep enough how to use them (how to use them with parameters and column names).
And there is a very strange thing (at least for me): You can use backticks either way:
UPDATE customers SET Name = `Name`;
//or
UPDATE customers SET `Name` = Name;
//or even
UPDATE customers SET `Name` = `Name`;
and they all work absolutely the same way.
Don't you think this is strange? Is this strange behavior explained somewhere?
Simplest way to distinguished between your parameter and column (if both name is same) is to add table name in your column name.
UPDATE customers SET customers.Name = Name;
Even you can also add database prefix like
UPDATE yourdb.customers SET yourdb.customers.Name = Name;
By adding database name you can perform action on more than 1 database from single store procedure.
I think that your first example is actually backwards. If you're trying to set the "Name" column to the "Name" input parameter, I believe it should be:
UPDATE customers SET `Name` = Name;
And for the second example, you can set table aliases the same way that you do in all other statements:
UPDATE customers AS c SET c.Name = Name;
Not necessarily correct, but a fair way to better argument/parameter management, as well readability with easier understanding, especially while working with the SQL;
DROP PROCEDURE IF EXISTS spTerminalDataDailyStatistics; DELIMITER $$
CREATE PROCEDURE spTerminalDataDailyStatistics(
IN TimeFrom DATETIME,
IN DayCount INT(10),
IN CustomerID BIGINT(20)
) COMMENT 'Daily Terminal data statistics in a date range' BEGIN
# Validate argument
SET #TimeFrom := IF(TimeFrom IS NULL, DATE_FORMAT(NOW(), '%Y-%m-01 00:00:00'), TimeFrom);
SET #DayCount := IF(DayCount IS NULL, 5, DayCount);
SET #CustomerID := CustomerID;
# Determine parameter
SET #TimeTo = DATE_ADD(DATE_ADD(#TimeFrom, INTERVAL #DayCount DAY), INTERVAL -1 SECOND);
# Do the job
SELECT DATE_FORMAT(TD.TerminalDataTime, '%Y-%m-%d') AS DataPeriod,
COUNT(0) AS DataCount,
MIN(TD.TerminalDataTime) AS Earliest,
MAX(TD.TerminalDataTime) AS Latest
FROM pnl_terminaldata AS TD
WHERE TD.TerminalDataTime BETWEEN #TimeFrom AND #TimeTo
AND (#CustomerID IS NULL OR TD.CustomerID = #CustomerID)
GROUP BY DataPeriod
ORDER BY DataPeriod ASC;
END $$
DELIMITER ;
CALL spTerminalDataDailyStatistics('2021-12-01', 2, 1801);
Using backticks in MySQL query syntax is documented here:
http://dev.mysql.com/doc/refman/5.0/en/identifiers.html
So yes, your first example (using backticks) is correct.
Here is the link you are asking for:
http://dev.mysql.com/doc/refman/5.0/en/identifiers.html
The backticks are called "identifier quote" in MySql