I would like to know if it is possible and how I could do a where clause in ActiveAndroid with a "IN" clause.
For example, I would like do do something like this:
new Select().from(Table).where("id in ?", list).execute()
The query should work almost as is - ActiveAndroid reduces your SELECT to SQL anyway.
For example, the following LIKE query works for me:
public static List<Record> search(String searchTerm) {
return new Select().from(Record.class)
.where("Data LIKE ?", new String[]{'%' + searchTerm + '%'})
.orderBy("Name ASC")
.execute();
}
where search term is '%searchTerm%'
If you are having difficulty, you can query the DB directly, ie:
mRecordList = SQLiteUtils.rawQuery(Record.class,
"SELECT * from Records where Data LIKE ?",
new String[]{'%' + searchTerm + '%'});
*/
new Select().from(Table).where("id in (1,2)").execute()
use this link for IN clause in activeandroid. Its bit difficult but check the answer given by jlhonora. it worked for me
https://github.com/pardom/ActiveAndroid/issues/392
Related
I am a little lost on how to incorporate TWO Where in my sql statement in my asp.
I am trying to get the userID and password entered previously and compare it with what I have in my database created on SQL:
I think my problem comes from my double quotation and single quotation.
UserID is a number in my database and Password is a short text.
var mycon = new ActiveXObject("ADODB.Connection");
var myrec = new ActiveXObject("ADODB.Recordset");
mycon.Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Users\\Omnivox.mdb");
var txtpassword = Request.QueryString("txtpassword");
var txtuserID = parseInt (Request.QueryString("txtuserID"));
var sql;
sql = "SELECT UserID, UserPassword FROM UserOmnivox WHERE UserID=" +txtuserID+ " AND UserPassword='" + txtpassword + "';";
myrec.Open(sql, mycon);
thank you
UPDATE: It is still not working. The error massage is : no value given for one or more required parameters for the line myrec.Open(sql,mycon)
Change
sql = "SELECT * FROM UserOmnivox WHERE UserID=" +txtuserID "AND UserPassword="'+txtpassword';
to
sql = "SELECT * FROM UserOmnivox WHERE UserID=" +txtuserID + " AND UserPassword='"+txtpassword+"'";
If you'd done any kind of basic debugging, like LOOKING at the query string you're generating, you'd have seen this:
sql = "SELECT [..snip..] UserID=" +txtuserID "AND UserPassword="'+txtpassword
^^--- no space
^--- missing +
which produces
SELECT .... UserID=1234AND userPassword
^^---syntax error, no such field '1234AND'
And then, yes, your quotes are wrong too
sql = "SELECT ... UserID=" +txtuserID "AND UserPassword="'+txtpassword
^------------------^-- one string
^-----------------^-- another string
^---???
It should be
sql = "SELECT * FROM UserOmnivox WHERE UserID=" +txtuserID + " AND UserPassword='" + txtpassword + "';";
I find another more flexible solution is better. Sometimes based on conditions you have one where condition, in others you have zero, and in others you have two. If you go down these paths they don't solve that issue. The following does.....
Some sql query
where 1=1 -- ## A condition that will always be true and does nothing to your query.
and first optional where clause
and second optional where clause
This way if you don't have the first where clause in a given situation but you do have the second you are not missing the words "where". You always have the where and you optionally add any array of "and" parts to your where statement. 100% flexibility in this method works for all challenges. Plus it is easier to follow code once you get past the wtf is this 1=1 nonsense reaction.
I am working on a C# desktop application. I want to create a search functionality. Now the problem is that i am using around 8 textboxes. Different permutations of textboxes could be populated and the resulting 'sql where' condition should only include those textboxes values which are not null. Now one pathetic way is to use a zillion 'if and else' which obviously is laborious. Any other way to do this?
You need just one query with filled WHERE to use all parameters like this
select ...
from ...
WHERE
(firstNameColumn=:firstNameParam or :firstNameParam is null)
AND (lastNameColumn=:lastNameParam or :lastNameParam is null)
AND (...)
I would like to make a point of first checking is the paramtere null, then use it to compare with column values.
Since you are generating query in C#, try old-Chinese approach from Ming period of using default condition where 1=1 just to avoid checking did you already had first condition :)
string query = "select ... from ... join ... on ... where 1=1";
//suposedly you have value of one search box in variable called "item_name"
if(string.IsNullOrWhiteSpace(item_name) == false)
{
query += " and Order_Line.Name ='" + item_name + "'";
}
and so on for other fields.
What you are trying to do in order to avoid ifs is not really a good approach. Look at this:
string query = " select ... where Order_Line.Name = '" + item_name + "'";
What will be the resulting string if item_name is actually null?
EDIT: the resulting query would be
where Order_Line.Name = '' or Order_Line.Name is null
which is not what you want. You want every row if that search field is empty, menaing it shouldn't have anu effect on search. That's why you need condition to see will you include this column in where clause in the first place.
I've been thinking this for a while. Is there an easy way to use the result querying a database twice without storing the result of the query in some variable? Say I have a
string ResearchAdmin;
where I want to put the 'FirstName' and 'Surname' found in 2 different columns in a 'ProjectResearcher' table in the database. Can I query the database just once (using say entity framework), and get both columns without storing the entire table's data.
To illustrate my point, doing the code below will I think query the database twice, once to get the 'FirstName', once to get the 'Surname':
ResearchAdmin = db.ProjectResearcher.FirstOrDefault(r => r.ProjectId == project.ProjectId).Researcher.FirstName + " " + db.ProjectResearcher.FirstOrDefault(r => r.ProjectId == project.ProjectId).Researcher.Surname
To run the query once I can do the following:
Researcher researchAdmin = db.ProjectResearcher.FirstOrDefault(r => r.ProjectId == project.ProjectId).Researcher;
String researchAdminName = researchAdmin.FirstName + " " + researchAdmin.Surname;
What I'm wondering is if I can do the first option somehow without querying the database twice.
You could do something like this:
String researchAdminName = db.ProjectResearcher.Where(r => r.ProjectId == project.ProjectId)
.Select(r => r.FirstName + " " + r.Surname).FirstOrDefault();
Just have to be a little careful that whatever you are putting into the select statement is supported by linq to entities, but simple string concatenation is.
Thewads answer looks correct and it will give you what you need.
An alternative:
Wrap logic in Stored Proc (certainly an overkill here) but for more complex manipulation its prob. better as SQL server will have a cached plan and will be faster.
Is it possible to use a prepared statement for the FROM clause?
I'm trying to do this:
PreparedStatement preStmType = conn.prepareStatement("SELECT * FROM ? WHERE article_id = ?");
preStmType.setString(1, rsetArticle.getString(5));
preStmType.setInt(2, rsetArticle.getInt(1));
It does not seem to work. When I remove the argument for the FROM clause and use it only in the where, it works, but I would like to generate the FROM dynamically too.
Nope, you can't
Prepared statements supports data literals only.
Speaking of this particular case, why do you want to generate fieldlist dynamically? If you don't know what field you need - just select all and then pick one from the returned row
Are you using Java?
How about trying this:
String qryStr = "SELECT * FROM "+rsetArticle.getString(5)+" "
qryStr =qryStr + "WHERE article_id = ?"
PreparedStatement preStmType = conn.prepareStatement(qryStr);
preStmType.setInt(1, rsetArticle.getInt(1));
I'm wanting to let a user search rows in a database by specifying a keyword to look for. There are a few fields I would like to look in for this keyword, one of which is a uniqueidentifier. The problem is, if the keyword is not a GUID, I get the following error message:
Conversion failed when converting from a character string to uniqueidentifier
The SQL I'm using to run the search looks something like this:
// do not use
string sql = #"SELECT *
FROM [MyTable]
WHERE [MyTable].[TableID] = '" + keyword + "'";
WARNING: this is just example code - DO NOT write sql commands like this as it creates a security risk
How do I write my SQL select statement such that it will not fail when keyword is not a GUID?
string sql;
Guid id;
if (Guid.TryParse(keyword, out id))
{
sql = #"SELECT *
FROM [MyTable]
WHERE [MyTable].[TableID] = '" + keyword + "'";
}
else
{
sql = //search by other way
}
Does this work for you?
string sql = #"SELECT *
FROM [MyTable]
WHERE convert(varchar,[MyTable].[TableID]) = '" + keyword + "'";
I know this doesn't really help you today, but may help future readers. In SQL Server 2012 you will be able to use TRY_CONVERT:
string sql = #"SELECT *
FROM dbo.[MyTable]
WHERE [TableID] = TRY_CONVERT(UNIQUEIDENTIFIER, '" + keyword + "');";
But what you really should be doing is passing the parameter as a strongly typed GUID, and handling the error (using try/catch) in the client program when someone enters something that isn't a GUID.