CODEWITHSUNDEEP
javajdbc
Java P
Java P

Reputation: 2281

Set parameters dynamically to prepared Statement in JDBC

I have a common class for all DAO's where we will read queries and execute them as below. I will send parameters from DAO to this class.

Connection connection = Queries.getConnection();
String query = Queries.getQuery(queryName);//Queries i will get from xml
PreparedStatement preparedStatement =  connection.prepareStatement(query);

what is the best way to set parameters dynamically to prepared Statement in JDBC. I believe, we don't have named parameters concept in JDBC as we have in spring JDBC. We are only simple JDBC in our project.

Upvotes: 8

Views: 72618

Answers (4)

Vlad Troyan
Vlad Troyan

Reputation: 157

Good way is to use Map

Map<String, Object> params = new HashMap<>();
params.put("id",0);
params.put("name","test");
//more params here...


String sql = "SELECT * FROM test";

boolean first = true;

for (String paramName : params.keySet()) {
    Object paramValue = params.get(paramName);
    if (paramValue != null) {
        if (first){
            sql += " where " + paramName + "=?";
            first = false;
        } else {
            sql += " and " + paramName + "=?";
        }
    }
}

Connection connection = DataSource.getInstance().getConnection();

ps = connection.prepareStatement(sql);

int paramNumber = 1;
for (String paramName : params.keySet()) {
    Object paramValue = params.get(paramName);
    if (paramValue != null) {
        if (param instanceof Date) {
            ps.setDate(paramNumber, (Date) param);
        } else if (param instanceof Integer) {
            ps.setInt(paramNumber, (Integer) param);
        //more types here...
        } else {
            ps.setString(paramNumber, param.toString());
        }
        paramNumber ++;
    }
}

Upvotes: 6

lkdg
lkdg

Reputation: 1051

Maybe this interesting to you Named Parameters for PreparedStatement

Upvotes: 1

oleg
oleg

Reputation: 197

Look at this page example. Your query should contain ? in place where you want to set value.

String query = "update COFFEES set SALES = ? where COF_NAME = ?";

And you can easily set values like this

preparedStatement.setInt(1, 100);
preparedStatement.setString(2, "French_Roast");

Upvotes: 5

Andrey Borisov
Andrey Borisov

Reputation: 3170

write something like this:

public static int mapParams(PreparedStatement ps, Object... args) throws SQLException {
    int i = 1;
    for (Object arg : args) {         
         if (arg instanceof Date) {
        ps.setTimestamp(i++, new Timestamp(((Date) arg).getTime()));
    } else if (arg instanceof Integer) {
        ps.setInt(i++, (Integer) arg);
    } else if (arg instanceof Long) {
        ps.setLong(i++, (Long) arg);
    } else if (arg instanceof Double) {
        ps.setDouble(i++, (Double) arg);
    } else if (arg instanceof Float) {
        ps.setFloat(i++, (Float) arg);
    } else {
        ps.setString(i++, (String) arg);
    }
   }
  }
}

and in the queries just use '?' where you need to set the parameter.

I know that this is old school code, but just to give some minimalistic example...

Upvotes: 9

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