Android Question Best way to do this concatenation?

[Robert Valentino]

I have some code that I am converting that use to be all & for concatenation of strings, moving to smart strings and was wondering what was best

In the second part of this building the SQL statement I use a & to and on the 2nd part of the string

            mSQLStatement =  $"DELETE FROM ${DEFINE_DB_TiesTableName} where ${DEFINE_DB_TagTiesFWID} = ${FWID}"$
            
            If  FWTypeID > 0 Then
                mSQLStatement = mSQLStatement &$"  and  ${DEFINE_DB_TagTiesFWTypeID} = ${FWTypeID}"$
            End If

OR

Maybe me wonder should I just put the first part of the command in the smart string as well?

            mSQLStatement =  $"DELETE FROM ${DEFINE_DB_TiesTableName} where ${DEFINE_DB_TagTiesFWID} = ${FWID}"$
            
            If  FWTypeID > 0 Then
                mSQLStatement = $"${mSQLStatement}  and  ${DEFINE_DB_TagTiesFWTypeID} = ${FWTypeID}"$
            end if

Just wondering

 

[Mahares]

Just wondering

mSQLStatement = $"DELETE FROM ${DEFINE_DB_TiesTableName} 
    WHERE ${DEFINE_DB_TagTiesFWID} = ${FWID}
    AND  ${DEFINE_DB_TagTiesFWTypeID} = ${FWTypeID}"$

Or if you can use a parameterized query, it is better:

 mSQLStatement = $"DELETE FROM ${DEFINE_DB_TiesTableName}
    WHERE ${DEFINE_DB_TagTiesFWID} = ?
    AND ${DEFINE_DB_TagTiesFWTypeID} = ?"$

 

[Robert Valentino]

Think you missed what I was asking.

Your statements are fine if I have both parameters.

But thanks for the idea

 

[Mahares]

Think you missed what I was asking.

Why don't you explain yourself better then, if I missed what you are asking. Maybe some one will not miss what you are asking. I gave you 2 options, not one. You choose what works for you. Tell us what I missed from your question.

 

[aeric]

I think OP wants an SQL command to handle a scenario where FWTypeID is optional (only applies when it is a positive value).

One line code:

mSQLStatement = $"DELETE FROM ${DEFINE_DB_TiesTableName} WHERE ${DEFINE_DB_TagTiesFWID} = ${FWID}
${IIf(FWTypeID > 0, $" AND ${DEFINE_DB_TagTiesFWTypeID} = ${FWTypeID}"$, "")}"$

 

[Mahares]

OP wants an SQL command to handle a scenario where FWTypeID is optional (only applies when it is a positive value).

Glad you read the OP mind. However,DEFINE_DB_TagTiesFWID and DEFINE_DB_TagTiesFWTypeID represent columns. I don't think you can use variables for the column name. If they are actual column names and not variables, then you need to remove the string literal tags from both columns. I wish the OP explained his statement more clearly so there is less guessing.

 

[aeric]

I also not sure. The column names may have different prefix for different databases. Who knows.

 

[Robert Valentino]

Aeric, like your idea

the DEFINE are const

    Private Const DEFINE_DB_TagTiesFWID                                 As String = "FWID"
    Private Const DEFINE_DB_TagTiesFWTypeID                         As String = "FWTypeID"