I am getting QuerySyntaxException while trying to execute this line of code,
String sqlQuery = "SELECT * FROM t_student01";
This is how it looks like in the editor:
Any ideas?
Your HQL syntax should either be:
SELECT t FROM YourEntityClass t
Or, you can actually omit the SELECT portion entirely:
FROM YourEntityClass
Related
Say I have a class variable restemail which stores the email id I need to use to sort out from the select statement in SQLite (Python). Whenever I refer to that variable after my WHERE clause, SQLite treats it as a column and returns an error saying that such a column doesn't exist. Something like this:
restemail=StringVar()
Password=StringVar()
def database(self):
conn = sqlite3.connect('data.db')
with conn:
cursor=conn.cursor()
strrest = self.restemail
cursor.execute('SELECT * FROM Restaurant3 WHERE restemail = strrest')
Can someone tell me how to use a variable inside my SQL queries without it being treated as a column name?
Any help will be appreciated.
Try the sqlite3 variable substitution syntax:
cursor.execute('SELECT * FROM Restaurant3 WHERE restemail = ?', (strrest,))
I have the following C# code to select a column from a table that is on a linked server:
var query2 = $#"select [FileName] from [AMS_H2H].[H2H].[dbo].[FileReconciliation] where ProductCode = #productCode";
LayZConnection(); //make the db connection
var candidates = _dbConnection.Query<int>(query2, new { productCode = "ACHDH" });
When running it, I get the following error:
"Input string was not in a correct format."
If my query is instead the following, where I select all columns, it works:
var query2 = $#"select * from [AMS_H2H].[H2H].[dbo].[FileReconciliation]
What is the correct format to select just the FileName. Btw, the first query works fine from MSSMS.
You're specifying a type of int in Query<int>, which will cause Dapper to try and map the result of the query to an integer, however your query is returning a filename in select [FileName], which would suggest that it is a string.
Changing the type Query<string> should solve the issue.
More information on Dapper's Query method is available in Dapper's documentation
I'm generating SQL programmatically so that, based on certain parameters, the query that needs to be executed could be different (i.e., tables used, unions, etc). How can I insert a string like this: "select * from table", into a %%sql block? I know that using :variable inserts variable into the %%sql block, but it does so as a string, rather than sql code.
The answer was staring me in the face:
query="""
select
*
from
sometable
"""
%sql $query
If you want to templatize your queries, you can use string.Template:
from string import Template
template = Template("""
SELECT *
FROM my_data
LIMIT $limit
""")
limit_one = template.substitute(limit=1)
limit_two = template.substitute(limit=2)
%sql $limit_one
Source: JupySQL documentation.
Important: If you use this approach, ensure you trust/sanitize the input!
I'm able to do:
var codeStation = from Code in ent.Role
where Code.Code.StartsWith("S_")
select Code;
(ent: being my Entity for my Database)
That gives me :
S_ANC
S_ATL
S_BNA
S_BOS
S_BRU
S_CLT
.....
S_YXE
S_YXY
S_YYC
S_YYG
S_YYT
S_YYZ
How can I accomplish the equivalent of the following SQL query?
SELECT Substring(Codes,3,6)
FROM Role
WHERE Codes LIKE 'S%'
Thanks!
var codeStation = from Code in ent.Role
where Code.Code.StartsWith("S_")
select RoleName.Substring(3,6);
Your LINQ query can select any legal C# expression you want, including method calls on the field names. So, you can do something like this:
var codeStation = from Code in ent.Role
where Code.Code.StartsWith("S_")
select Code.RoleName.SubString(3,6);
what is wrong with this sql query. i cant figure it out.
$query = "SELECT *
FROM tagPairs
WHERE (tag1Id IN ($tag1Id, $tag2Id))
AND (tag2Id IN ($tag1Id, $tag2Id))";
error code:
Couldn't execute query: 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 ' ))
AND (tag2Id IN (, ))' at line 3
thanks in advance!
$tag1Id and $tag2Id are both null, or empty strings. The simplest solutions is probably to explicitly cast them into numerical values:
$tag1Id = intval($tag1Id);
$tag2Id = intval($tag2Id);
$query = "SELECT *
FROM tagPairs
WHERE (tag1Id IN ($tag1Id, $tag2Id))
AND (tag2Id IN ($tag1Id, $tag2Id))";
$tag1Id and $tag2Id are empty.
That's why your error says (tag2Id IN (, )).
Your $tag1Id and $tag2Id are empty strings. Assign a value to them and it should work fine.
Also, selecting * is a bad idea. Select the columns you need explicity.