Where the SQL query is wrong?

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I am using VB.net (2010) for database management with a MSAccess 2003 database on Windows10. For deletion of a record I using sql query:

VB.NET

query = "DELETE * FROM monthOverAll WHERE actDate =" + catchDate + "AND doneBy =" + catchDoneBy + "AND (Training > 0) OR (EA > 0) OR (OFT > 0) OR (FLD > 0) OR (splEvent > 0) OR (farmProd > 0) OR (CovidActivity > 0) OR (CFLD > 0))"

where:
monthOverAll is the table
actDate, doneBy, Training, EA, OFT, FLD, splEvent, farmProd, CovidActivity, CFLD are database fields.
catchDate, catchDoneBy are variables.

while executing it I get the following error. Can anyone please help me with this. Thanks in advance.

Syntax error (missing operator) in query expression 'actDate =03-Aug-21AND doneBy =DR GPM SINGHAND (Training > 0) OR (EA > 0) OR (OFT > 0) OR (FLD > 0) OR (splEvent > 0) OR (farmProd > 0) OR (CovidActivity > 0) OR (CFLD > 0))'.

What I have tried:

I have tried all sorts combinations but nothing seems to work.

Posted 2-Aug-21 22:50pm

Krishi Vigyan Kendra Allahabad

Updated 2-Aug-21 23:08pm

Maciej Los

v3

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2 solutions

Solution 1

Do NOT use concatenated strings! Due to the Sql Injection[^] use parameterized queries instead.

See:
Create Parameterized Queries in ADO.NET -- Visual Studio Magazine[^]
How and Why to Use Parameterized Queries - Microsoft Tech Community[^]

Posted 2-Aug-21 23:08pm

Maciej Los

Updated 2-Aug-21 23:09pm

v2

Comments

CPallini 3-Aug-21 5:09am

5.

Maciej Los 3-Aug-21 9:40am

Thank you, Carlo!

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Richard Deeming · Accepted Answer · 2021-08-02T23:08:00

Your code is vulnerable to SQL Injection[^]. NEVER use string concatenation to build a SQL query. ALWAYS use a parameterized query.

Fix that security vulnerability, and remove the extra closing parenthesis, and you'll also fix your error.

VB.NET

Using cmd As New OleDbCommand()
    cmd.Connection = conn
    
    cmd.CommandText = "DELETE FROM monthOverAll WHERE actDate = ? AND doneBy = ? And (Training > 0) OR (EA > 0) OR (OFT > 0) OR (FLD > 0) OR (splEvent > 0) OR (farmProd > 0) OR (CovidActivity > 0) OR (CFLD > 0)"
    cmd.Parameters.AddWithValue("actDate", catchDate)
    cmd.Parameters.AddWithValue("doneBy", catchDoneBy)
    
    cmd.ExecuteNonQuery()
End Using

Everything you wanted to know about SQL injection (but were afraid to ask) | Troy Hunt[^]
How can I explain SQL injection without technical jargon? | Information Security Stack Exchange[^]
Query Parameterization Cheat Sheet | OWASP[^]