I Need help for fetch records from table using Go.
My Problem is that i'm writing MySQL query and add another where clause i.e HPhone number, Here HPhone number inserted in data base with format like 999-999-9999.And i passed this HPhone Number in format like 9999999999. which is not matching with correct data base field value. And i used SUBSTRING for add hyphen between numbers but it does not get records but when i passed like 999-999-9999 without SUBSTRING it return records.
Here i demonstrate how i used this.
strQry = `SELECT * from table WHERE Depot = ?`
if HPhone != "" {
strQry += ` AND HPhone = ?`
}
queryArgs := []interface{}{RouteAvailability.Depot}
if HPhone != "" {
queryArgs = append(queryArgs, "SUBSTRING("+HPhone+",1,3)"+"-"+"SUBSTRING("+HPhone+",4,3)"+"-"+"SUBSTRING("+HPhone+",7,4)")
}
Help would be appreciated.
Thanks in advance.
Instead of SUBSTRING you can use REPLACE like so:
queryArgs := []interface{}{RouteAvailability.Depot}
if HPhone != "" {
strQry += ` AND REPLACE(HPhone, '-', '') = ?`
queryArgs = append(queryArgs, HPhone)
}
If possible I would suggest you normalize your data, i.e. decide on a canonical format for a particular data type and everytime your program receives some input that contains that data type you format it into its canonical form, that way you can avoid having to deal with SUBSTRING, or REPLACE, or multiple inconsistent formats etc.
This won't work as you are using prepared statements, and the argument you are building when HPhone is not empty will be used in escaped form - so when executing the query, it won't compare the HPhone values with the computed result of some substring, but with a string containing SUBSTRING(9999...
Related
let r={ email:faker.internet.email() } ;
connection_var.query("insert into users set ?",r, function(err,res){
if(err) throw err;
console.log(res);
} );
connection_var.end();
I wrote this code to insert a fake email addr in already existing database and into the users table just the problem is I am not fully able to understand what and how does the " SET ?" work and how is it relating to r and what if r has more than 1 key-value pairs
? is a placeholder. It gets replaced with all the keys and values in the object passed as the next argument. So if you have
let r = {col1: 1, col2: "abc", col3: 999};
the query will become
insert into users set col1 = 1, col2 = 'abc', col3 = 999
You have 2 separated things here
First is the SET clause (for the insert) that from the documentation:
A SET clause indicates columns explicitly by name, together with the value to assign each one.
link: https://dev.mysql.com/doc/refman/8.0/en/insert.html
The other part is the ? the according to the documentation of mysqljs:
... you can use ? characters as placeholders for values you would like to
have escaped
link: https://github.com/mysqljs/mysql
So, the SET indicates the assignment list of the insert and the ? escapes the values.
In MS Access I have a table with a Short Text field named txtPMTaskDesc in which some records contains numbers, and if they do, at different positions in the string. I would like to recover these numbers from the text string if possible for sorting purposes.
There are over 26000 records in the table, so I would rather handle it in a query over using VBA loops etc.
Sample Data
While the end goal is to recover the whole number, I was going to start with just identifying the position of the first numerical value in the string. I have tried a few things to no avail like:
InStr(1,[txtPMTaskDesc],"*[0-9]*")
Once I get that, I was going to use it as a part of a Mid() function to pull out it and the character next to it like below. (its a bit dodgy, but there is never more than a two-digit number in the text string)
IIf(InStr(1,[txtPMTaskDesc],"*[0-9]*")>0,Mid([txtPMTaskDesc],InStr(1,[txtPMTaskDesc],"*[0-9]*"),2)*1,0)
Any assistance appreciated.
If data is truly representative and number always preceded by "- No ", then expression in query can be like:
Val(Mid(txtPMTaskDesc, InStr(txtPMTaskDesc, "- No ") + 5))
If there is no match, a 0 will return, however, if field is null, the expression will error.
If string does not have consistent pattern (numbers always in same position or preceded by some distinct character combination that can be used to locate position), don't think can get what you want without VBA. Either loop through string or explore Regular Expressions aka RegEx. Set reference to Microsoft VBScript Regular Expressions x.x library.
Function GetNum(strS AS String)
Dim re As RegExp, Match As Object
Set re = New RegExp
re.Pattern = "[\d+]+"
Set Match = re.Execute(strS)
GetNum = Null
If Match.Count > 0 Then GetNum = Match(0)
End Function
Input of string "Fuel Injector - No 1 - R&I" returns 1.
Place function in a general module and call it from query.
SELECT table.*, GetNum(Nz(txtPMTaskDesc,"")) AS Num FROM table;
Function returns Null if there is no number match.
Well, does the number you want ALWAYS have a - No xxxx - format?
If yes, then you could have this global function in VBA like this:
Public Function GNUM(v As Variant) As Long
If IsNull(v) Then
GNUM = 0
Exit Function
End If
Dim vBuf As Variant
vBuf = Split(v, " - No ")
Dim strRes As String
If UBound(vBuf) > 0 Then
strRes = Split(vBuf(1), "-")(0)
GNUM = Trim(strRes)
Else
GNUM = 0
End If
End Function
Then your sql will be like this:
SELECT BLA, BLA, txtPMTaskDesc, GNUM([txtPMTaskDesc] AS TaskNum
FROM myTable
So you can create/have a public VBA function, and it can be used in the sql query.
It just a question if " - No -" is ALWAYS that format, then THEN the number follows this
So we have "space" "-" "space" "No" "space" "-" -- then the number and the " -"
How well this will work depends on how consistent this text is.
I've been stuck on a GORM issue for about a full day now. I need to be able to filter a messages table on any of 4 things: sender, recipient, keyword, and date range. It also has to paginate. Filtering by sender and recipient is working, and so is pagination. So far this is the query that I have come up with, but it does not seem to work for date ranges or keywords.
Here is how I am selecting from MySQL
db.Preload("Thread").Where(query).Scopes(Paginate(r)).Find(&threadMessages)
I am creating the query like this:
var query map[string]interface{}
Then based on which parameters I am passed, I update the query like this by adding new key values to the map:
query = map[string]interface{}{"user_id": sender, "recipient_id": recipient}
For dates it does not seem to work if I try something like this:
query = map[string]interface{}{"created_at > ?": fromDate}
And for a LIKE condition is also does not seem to work:
query = map[string]interface{}{"contents LIKE ?": keyword}
The reason I chose this approach is that I could not seem to get optional inputs to work in .Where since it takes a string with positional parameters and null positional parameters seem to cause MySQL to return an empty array. Has anyone else dealt with a complicated GORM issue like this? Any help is appreciated at this point.
Passing the map[string]interface{} into Where() only appears to work for Equals operations, or IN operations (if a slice is provided as the value instead).
One way to achieve what you want, is to construct a slice of clause.Expression, and append clauses to the slice when you need to. Then, you can simply pass in all of the clauses (using the ... operator to pass in the whole slice) into db.Clauses().
clauses := make([]clause.Expression, 0)
if mustFilterCreatedAt {
clauses = append(clauses, clause.Gt{Column: "created_at", fromDate})
}
if mustFilterContents {
clauses = append(clauses, clause.Like{Column: "contents", Value: keyword})
}
db.Preload("Thread").Clauses(clauses...).Scopes(Paginate(r)).Find(&threadMessages)
Note: If you're trying to search for content that contains keyword, then you should concatenate the wildcard % onto the ends of keyword, otherwise LIKE behaves essentially the same as =:
clause.Like{Column: "contents", Value: "%" + keyword + "%"}
My final solution to this was to create dynamic Where clauses based on which query params were sent from the client like this:
fields := []string{""}
values := []interface{}{}
If, for example, there is a keyword param:
fields = []string{"thread_messages.contents LIKE ?"}
values = []interface{}{"%" + keyword + "%"}
And to use the dynamic clauses in the below query:
db.Preload("Thread", "agency_id = ?", agencyID).Preload("Thread.ThreadUsers", "agency_id = ?", agencyID).Joins("JOIN threads on thread_messages.thread_id = threads.id").Where("threads.agency_id = ?", agencyID).Where(strings.Join(fields, " AND "), values...).Scopes(PaginateMessages(r)).Find(&threadMessages)
I need to clean JSON data that could look like:
{
"reference":"0000010-CAJ",
"product_code":"00000-10",
"var_name":"CAJ-1",
"doc_date":"2020-02-09T21:01:01-05:00",
"due_date":"2020-03-10T21:01:01-05:00",
}
However, this is just one of many other possibilities (is for a log aggregation that gets data from many sources).
I need to replace "-" with "_", but without break the dates like "2020-03-10T21:01:01-05:00", so can't simply cast to string and do a replace. I wonder if exist an equivalent of:
for (k,v) in json:
if is_text(v):
v = replace(...)
You can check with a regex if the value looks like a timestamp:
update the_table
set the_column = (select
jsonb_object_agg(
key,
case
when value ~ '^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}.*' then value
else replace(value, '-', '_')
end)
from jsonb_each_text(the_column) as t(key, value))
This iterates over all key/value pairs in the JSON column (using jsonb_each_text()) and assembles all of them back into a JSON again (using jsonb_object_agg()). Values that look like a timestamp are left unchanged, for all others, the - is replaced with a _.
I have a database that has stored values in a complicated, serialized array where one component is a string and another is the length of the characters of the string, in this format:
s:8:"test.com"
Where "s" holds the character length of the string in the quotations.
I would like to change the string from "test.com" to "testt.com", and I'm using the following statement in SQL:
UPDATE table SET row=(REPLACE (row, 'test.com','testt.com'))
However, this breaks the script in question, because it doesn't update the character length in the "s" preceding the string where "test.com" is stored.
I was wondering if there is a query I can use that would replace the string, and then also increment the value of this "s" preceding to where the replacement occurs, something like this:
UPDATE table SET row=(REPLACE (row, 's:' number 'test.com','s:' number+1 'testt.com'))
Does anyone know if this kind of query is even possible?
UPDATE table set row = concat('s:',length('testt.com'),':"testt.com"');
If you need to change exact string, then use exact query -
UPDATE table SET row = 's:9:"testt.com"' WHERE row = 's:8:"test.com"';
The string is a "serialized string".
If there are multiple strings to be replaced, it might be easier to create a script to handle this.
In PHP, it goes something like this:
$searchfor = serialize('test.com');
$replaceby = serialize('testt.com');
// strip last semicolon from serialized string
$searchfor = trim($searchfor,';');
$replaceby = trim($replaceby,';');
$query = "UPDATE table SET field = '$replaceby' WHERE field = '$searchfor';";
This way, you can create an exact query string with what you need.
Do fill in the proper code for db connection if necessary.