I am reading from a file where each line has 3-4 values that are separated by a tab. I have been trying to split the line up (based on the tabs) and store them in their own String, and then I push these values into a method that makes an SQL statement to INSERT INTO the values into a table as a new record.
My issue is that the split() method isn't quite working for me as it is giving me an `ArrayOutOfBoundsException' for the second value. But I am pretty sure there is an easier way to do what I am trying to do.
Currently I have:
// --------- Reading the topURLs file ---------
try {
scan = new Scanner (new File("TestURL"));
while (scan.hasNextLine()) {
String line = scan.nextLine();
String[] SQLValues = line.split("\\t");
String rank = SQLValues[0];
String websiteName = SQLValues[1];
String domain = SQLValues[2];
insertInto(conn, tableName, rank, websiteName, domain);
}
} catch (Exception e) {
e.printStackTrace();
}
And my insertIntomethod in case you would like to see:
public static void insertInto(Connection conn, String name, String rank, String websiteName, String domain) {
Statement st = null;
int rankInt = Integer.parseInt(rank);
try {
st = conn.createStatement();
st.execute("INSERT INTO " + name + "VALUES ('" + rankInt + "', '" + websiteName + "', '" + domain + "')");
} catch (SQLException e) {
e.printStackTrace();
}
}
I am aware this is messy, it's just all I know so far. The file TestURLs currently has two lines for the sake of testing (they are split using tabs in my file, I just don't know how to show that on here):
1 google com
2 cheese com
Is there something I am missing that causes the exception mentioned above? I thought that when I split line that it would put each separated word in the a different index of the array wordsArray. Instead, it seems like there is only one element in it at index 0.
If there is a better way to do what I am trying to do - that is, to take a line from a file, split the values, and put them into a table as a new record - could you point me in the right direction?
Any help is much appreciated.
try using
String[] SQLValues = line.split("\\s+");
you can use a greedy regular expression, which will match any number of white spaces including tabs. You can use "\s+" regex for this purpose.
Im creating a student profile for our project in school and it's my first time to make this.
This is my query for my jTable (mouseclicked) I've created in netbeans
int row = jTable1.getSelectedRow();
String tc = jTable1.getModel().getValueAt(row, 0).toString();
try {
String query ="select * from CAREPOINT_STUDENT where NAME="+tc+" ";
pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);
rs = (OracleResultSet) pst.executeQuery();
if(rs.next()){
String NAME_ID = rs.getString("NAME");
String AGE_ID = rs.getString("AGE");
String ADDRESS_ID = rs.getString("ADDRESS");
String NUM_ID = rs.getString("NUM");
String COURSE_ID = rs.getString("COURSE");
String SPECIAL_ID = rs.getString("SPECIAL");
String SCHOOL_ID = rs.getString("SCHOOL");
String DOWNPAY_ID = rs.getString("DOWNPAY");
String DISCOUNT_ID = rs.getString("DISCOUNT");
String BALANCE_ID = rs.getString("BALANCE");
String REVSCHED_ID = rs.getString("REVSCHED");
String EMAIL_ID = rs.getString("EMAIL");
NAME.setText(NAME_ID);
AGE.setText(AGE_ID);
ADDRESS.setText(ADDRESS_ID);
NUM.setText(NUM_ID);
COURSE.setText(COURSE_ID);
SPECIAL.setText(SPECIAL_ID);
SCHOOL.setText(SCHOOL_ID);
DOWNPAY.setText(DOWNPAY_ID);
DISCOUNT.setText(DISCOUNT_ID);
BALANCE.setText(BALANCE_ID);
REVSCHED.setText(REVSCHED_ID);
EMAIL.setText(EMAIL_ID);
}
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
}
}
When I run the program and tried to click the data (A Student Profile like name,age,school, etc..) that I created and printed inside the jtable (mouseclicked), I get this problem "ORA-00933: SQL command not properly ended"
Aside from that, I also have another problem which I created 2 jbutton called "DELETE" which means it will delete the data(Student profile) that I filled up and "UPDATE" which means to reedit the data(Student profile) that I filled up.
this is the query of my "DELETE" jbutton in netbeans
try {
String query;
query = "DELETE FROM CAREPOINT_STUDENT where NAME="+NAME.getText()+" ";
pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);
pst.execute();
JOptionPane.showMessageDialog(null, "Successfully deleted!");
fetch();
} catch (Exception e) {
JOptionPane.showMessageDialog(null, e);
}
}
and this is the query of my "UPDATE" jbutton in netbeans
try {
String query;
query = "update CAREPOINT_STUDENT set AGE=?,ADDRESS=?,NUM=?,COURSE=?,SPECIAL=?,SCHOOL=?,DOWNPAY=?,DISCOUNT=?,BALANCE=?,REVSCHED=?,EMAIL=? where NAME="+NAME.getText()+"";
pst= (OraclePreparedStatement) ungabelio1.prepareStatement(query);
pst.setString(1,AGE.getText());
pst.setString(2,ADDRESS.getText());
pst.setString(3, NUM.getText());
pst.setString(4, COURSE.getText());
pst.setString(5, SPECIAL.getText());
pst.setString(6, SCHOOL.getText());
pst.setString(7, DOWNPAY.getText());
pst.setString(8, DISCOUNT.getText());
pst.setString(9, BALANCE.getText());
pst.setString(10, REVSCHED.getText());
pst.setString(11, EMAIL.getText());
pst.executeUpdate();
JOptionPane.showMessageDialog(null, "Successfully updated!");
fetch();
} catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
when I run the program and click those 2 buttons, I get the same problem "ORA-00936: missing expression"
I really appreciate and I hope that somebody would help me to fix this problem. So that I can gain some little knowledge about sql/oracle.
Sorry for my bad english.
Avoid concatenating parameters as strings; use prepared statements.
Otherwise you'll run in all kind of troubles, like escaping issues for special characters, SQL Injection, etc.
For example, a safer way of running your SQL statement could be:
String query = "select * from CAREPOINT_STUDENT where NAME = ?";
pst = (OraclePreparedStatement) ungabelio1.prepareStatement(query);
pst.setString(1, tc);
rs = (OracleResultSet) pst.executeQuery();
Note: Assembling a SQL statement as a string is still useful for cases when you want to do some dynamic SQL. Even then, use ? for parameters and apply them as shown above.
You may need some extra single quotes so you query will read:
select * from CAREPOINT_STUDENT where NAME='Entered name';
Adjust your code:
String query ="select * from CAREPOINT_STUDENT where NAME='"+tc+"' ";
I have created a table register in SQL with field username. In the JFrame when a user enters username there is a JButton for checking the username availability. For this I have used the code below:
String sqlstmt = "select username from register where username='" +
jTextField1.getText() + "'";
try {
st = con.prepareStatement(sqlstmt);
stmt = con.createStatement();
rs = st.executeQuery(sqlstmt);
if (rs.next()) {
JOptionPane.showMessageDialog(null,"found");
} else {
JOptionPane.showMessageDialog(null,"not found");
}
} catch(SQLException e) {
JOptionPane.showMessageDialog(null,"sql error");
}
when executing this query, it is seen that data is empty. Or if I put rs.getString("username") inside the if (rs.next), it shows the "sql error" message.
You're mixing Statements and PreparedStatements here.
The best approach here would probably be to use a PreparedStatement, which would take care of any funky characters from your input, and offer protection against SQL injection:
// SQL statement to prepare.
// Note the lack of single quotes (') in the parameter
String sqlstmt= "select username from register where username = ?";
// Prepare the statement
PreparedStatement st = con.prepareStatement(sqlstmt);
// Bind the argument
st.setString(1, jTextField1.getText());
// Execute
ResultSet rs = st.executeQuery();
// Rest of the code to handle results...
Note:
This example omits error handling (e.g., try-catch constructs) in favor of clarity.
I've read Give me Parameterized SQL or give me death numerous times.
The advantage of Parameterized SQL for Strings, Dates, and floating-point numbers is very obvious and indisputable.
My question is: what about ints?
I ask because, oftentimes, if I'm writing a query or update and the only parameter is an int, I'll just write an inline sql and append the int as a shortcut ("select * from table where id = " + id).
My question: Are there any advantages to using Parameterized SQL for ints alone?
To illustrate with Java:
Are there any advantage to this:
Connection conn;
int id;
String sql = "select * from table where id = ?";
try (PreparedStatement p_stmt = conn.prepareStatement(sql)) {
p_stmt.setInt(1, id);
ResultSet results = p_stmt.executeQuery();
// ...
} catch (SQLException e) {
// ...
}
over this:
Connection conn;
int id;
String sql = "select * from table where id = " + id;
try (Statement stmt = conn.createStatement()) {
ResultSet results = stmt.executeQuery(sql);
// ...
} catch (SQLException e) {
// ...
}
I would say the biggest advantage would be consistency. If you decide that all SQL built by string concatenation is "wrong", it's easier to verify that your code is "right", compared to a rule like "All SQL built by string concatenation is wrong, except that which deals with ints as parameters".
Another case, say: down the line, you want to introduce sorting or grouping to the query, suddenly, your line turns into something like this:
String sql = "select * from table where id = " + id + " order by somecolumn";
And hopefully you remembered the space before order. And that everyone after you does also.
There is much to be said for doing things only one way, especially when that one way is the right thing most of the time.
I am trying to search an XML field within a table, This is not supported with EF.
Without using pure Ado.net is possible to have native SQL support with EF?
For .NET Framework version 4 and above: use ObjectContext.ExecuteStoreCommand() if your query returns no results, and use ObjectContext.ExecuteStoreQuery if your query returns results.
For previous .NET Framework versions, here's a sample illustrating what to do. Replace ExecuteNonQuery() as needed if your query returns results.
static void ExecuteSql(ObjectContext c, string sql)
{
var entityConnection = (System.Data.EntityClient.EntityConnection)c.Connection;
DbConnection conn = entityConnection.StoreConnection;
ConnectionState initialState = conn.State;
try
{
if (initialState != ConnectionState.Open)
conn.Open(); // open connection if not already open
using (DbCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.ExecuteNonQuery();
}
}
finally
{
if (initialState != ConnectionState.Open)
conn.Close(); // only close connection if not initially open
}
}
Using Entity Framework 5.0 you can use ExecuteSqlCommand to execute multi-line/multi-command pure SQL statements. This way you won't need to provide any backing object to store the returned value since the method returns an int (the result returned by the database after executing the command).
Sample:
context.Database.ExecuteSqlCommand(#
"-- Script Date: 10/1/2012 3:34 PM - Generated by ExportSqlCe version 3.5.2.18
SET IDENTITY_INSERT [Students] ON;
INSERT INTO [Students] ([StudentId],[FirstName],[LastName],[BirthDate],[Address],[Neighborhood],[City],[State],[Phone],[MobilePhone],[Email],[Enrollment],[Gender],[Status]) VALUES (12,N'First Name',N'SecondName',{ts '1988-03-02 00:00:00.000'},N'RUA 19 A, 60',N'MORADA DO VALE',N'BARRA DO PIRAÍ',N'Rio de Janeiro',N'3346-7125',NULL,NULL,{ts '2011-06-04 21:25:26.000'},2,1);
INSERT INTO [Students] ([StudentId],[FirstName],[LastName],[BirthDate],[Address],[Neighborhood],[City],[State],[Phone],[MobilePhone],[Email],[Enrollment],[Gender],[Status]) VALUES (13,N'FirstName',N'LastName',{ts '1976-04-12 00:00:00.000'},N'RUA 201, 2231',N'RECANTO FELIZ',N'BARRA DO PIRAÍ',N'Rio de Janeiro',N'3341-6892',NULL,NULL,{ts '2011-06-04 21:38:38.000'},2,1);
");
For more on this, take a look here: Entity Framework Code First: Executing SQL files on database creation
For Entity Framework 5 use context.Database.SqlQuery.
And for Entity Framework 4 use context.ExecuteStoreQuery
the following code:
public string BuyerSequenceNumberMax(int buyerId)
{
string sequenceMaxQuery = "SELECT TOP(1) btitosal.BuyerSequenceNumber FROM BuyerTakenItemToSale btitosal " +
"WHERE btitosal.BuyerID = " + buyerId +
"ORDER BY CONVERT(INT,SUBSTRING(btitosal.BuyerSequenceNumber,7, LEN(btitosal.BuyerSequenceNumber))) DESC";
var sequenceQueryResult = context.Database.SqlQuery<string>(sequenceMaxQuery).FirstOrDefault();
string buyerSequenceNumber = string.Empty;
if (sequenceQueryResult != null)
{
buyerSequenceNumber = sequenceQueryResult.ToString();
}
return buyerSequenceNumber;
}
To return a List use the following code:
public List<PanelSerialList> PanelSerialByLocationAndStock(string locationCode, byte storeLocation, string itemCategory, string itemCapacity, byte agreementType, string packageCode)
{
string panelSerialByLocationAndStockQuery = "SELECT isws.ItemSerialNo, im.ItemModel " +
"FROM Inv_ItemMaster im " +
"INNER JOIN " +
"Inv_ItemStockWithSerialNoByLocation isws " +
" ON im.ItemCode = isws.ItemCode " +
" WHERE isws.LocationCode = '" + locationCode + "' AND " +
" isws.StoreLocation = " + storeLocation + " AND " +
" isws.IsAvailableInStore = 1 AND " +
" im.ItemCapacity = '" + itemCapacity + "' AND " +
" isws.ItemSerialNo NOT IN ( " +
" Select sp.PanelSerialNo From Special_SpecialPackagePriceForResale sp " +
" Where sp.PackageCode = '" + packageCode + "' )";
return context.Database.SqlQuery<PanelSerialList>(panelSerialByLocationAndStockQuery).ToList();
}
Keep it simple
using (var context = new MyDBEntities())
{
var m = context.ExecuteStoreQuery<MyDataObject>("Select * from Person", string.Empty);
//Do anything you wonna do with
MessageBox.Show(m.Count().ToString());
}
public class RaptorRepository<T>
where T : class
{
public RaptorRepository()
: this(new RaptorCoreEntities())
{
}
public RaptorRepository(ObjectContext repositoryContext)
{
_repositoryContext = repositoryContext ?? new RaptorCoreEntities();
_objectSet = repositoryContext.CreateObjectSet<T>();
}
private ObjectContext _repositoryContext;
private ObjectSet<T> _objectSet;
public ObjectSet<T> ObjectSet
{
get
{
return _objectSet;
}
}
public void DeleteAll()
{
_repositoryContext
.ExecuteStoreCommand("DELETE " + _objectSet.EntitySet.ElementType.Name);
}
}
So what do we say about all this in 2017? 80k consultations suggests that running a SQL request in EF is something a lot of folk want to do. But why? For what benefit?
Justin, a guru with 20 times my reputation, in the accepted answer gives us a static method that looks line for line like the equivalent ADO code. Be sure to copy it well because there are a few subtleties to not get wrong. And you're obliged to concatenate your query with your runtime parameters since there's no provision for proper parameters. So all users of this method will be constructing their SQL with string methods (fragile, untestable, sql injection), and none of them will be unit testing.
The other answers have the same faults, only moreso. SQL buried in double quotes. SQL injection opportunities liberally scattered around. Esteemed peers, this is absolutely savage behaviour. If this was C# being generated, there would be a flame war. We don't even accept generating HTML this way, but somehow its OK for SQL. I know that query parameters were not the subject of the question, but we copy and reuse what we see, and the answers here are both models and testaments to what folk are doing.
Has EF melted our brains? EF doesn't want you to use SQL, so why use EF to do SQL.
Wanting to use SQL to talk to a relational DB is a healthy, normal impulse in adults. QueryFirst shows how this could be done intelligently, your sql in .sql file, validated as you type, with intellisense for tables and columns. The C# wrapper is generated by the tool, so your queries become discoverable in code, with intellisense for your inputs and results. End to end strong typing, without ever having to worry about a type. No need to ever remember a column name, or its index. And there are numerous other benefits... The temptation to concatenate is removed. The possibility of mishandling your connections also. All your queries and the code that accesses them are continuously integration-tested against your dev DB. Schema changes in your DB pop up as compile errors in your app. We even generate a self test method in the wrapper, so you can test new versions of your app against existing production databases, rather than waiting for the phone to ring. Anyone still need convincing?
Disclaimer: I wrote QueryFirst :-)