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How to pass query param to REST API to do a IN query in DB [duplicate]

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PreparedStatement IN clause alternatives?
(33 answers)
Closed 5 years ago.
Say that I have a query of the form
SELECT * FROM MYTABLE WHERE MYCOL in (?)
And I want to parameterize the arguments to in.
Is there a straightforward way to do this in Java with JDBC, in a way that could work on multiple databases without modifying the SQL itself?
The closest question I've found had to do with C#, I'm wondering if there is something different for Java/JDBC.

There's indeed no straightforward way to do this in JDBC. Some JDBC drivers seem to support PreparedStatement#setArray() on the IN clause. I am only not sure which ones that are.
You could just use a helper method with String#join() and Collections#nCopies() to generate the placeholders for IN clause and another helper method to set all the values in a loop with PreparedStatement#setObject().
public static String preparePlaceHolders(int length) {
return String.join(",", Collections.nCopies(length, "?"));
}
public static void setValues(PreparedStatement preparedStatement, Object... values) throws SQLException {
for (int i = 0; i < values.length; i++) {
preparedStatement.setObject(i + 1, values[i]);
}
}
Here's how you could use it:
private static final String SQL_FIND = "SELECT id, name, value FROM entity WHERE id IN (%s)";
public List<Entity> find(Set<Long> ids) throws SQLException {
List<Entity> entities = new ArrayList<Entity>();
String sql = String.format(SQL_FIND, preparePlaceHolders(ids.size()));
try (
Connection connection = dataSource.getConnection();
PreparedStatement statement = connection.prepareStatement(sql);
) {
setValues(statement, ids.toArray());
try (ResultSet resultSet = statement.executeQuery()) {
while (resultSet.next()) {
entities.add(map(resultSet));
}
}
}
return entities;
}
private static Entity map(ResultSet resultSet) throws SQLException {
Enitity entity = new Entity();
entity.setId(resultSet.getLong("id"));
entity.setName(resultSet.getString("name"));
entity.setValue(resultSet.getInt("value"));
return entity;
}
Note that some databases have a limit of allowable amount of values in the IN clause. Oracle for example has this limit on 1000 items.

Since nobody answer the case for a large IN clause (more than 100) I'll throw my solution to this problem which works nicely for JDBC. In short I replace the IN with a INNER JOIN on a tmp table.
What I do is make what I call a batch ids table and depending on the RDBMS I may make that a tmp table or in memory table.
The table has two columns. One column with the id from the IN Clause and another column with a batch id that I generate on the fly.
SELECT * FROM MYTABLE M INNER JOIN IDTABLE T ON T.MYCOL = M.MYCOL WHERE T.BATCH = ?
Before you select you shove your ids into the table with a given batch id.
Then you just replace your original queries IN clause with a INNER JOIN matching on your ids table WHERE batch_id equals your current batch. After your done your delete the entries for you batch.

The standard way to do this is (if you are using Spring JDBC) is to use the org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate class.
Using this class, it is possible to define a List as your SQL parameter and use the NamedParameterJdbcTemplate to replace a named parameter. For example:
public List<MyObject> getDatabaseObjects(List<String> params) {
NamedParameterJdbcTemplate jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);
String sql = "select * from my_table where my_col in (:params)";
List<MyObject> result = jdbcTemplate.query(sql, Collections.singletonMap("params", params), myRowMapper);
return result;
}

I solved this by constructing the SQL string with as many ? as I have values to look for.
SELECT * FROM MYTABLE WHERE MYCOL in (?,?,?,?)
First I searched for an array type I can pass into the statement, but all JDBC array types are vendor specific. So I stayed with the multiple ?.

I got the answer from docs.spring(19.7.3)
The SQL standard allows for selecting rows based on an expression that includes a variable list of values. A typical example would be select * from T_ACTOR where id in (1, 2, 3). This variable list is not directly supported for prepared statements by the JDBC standard; you cannot declare a variable number of placeholders. You need a number of variations with the desired number of placeholders prepared, or you need to generate the SQL string dynamically once you know how many placeholders are required. The named parameter support provided in the NamedParameterJdbcTemplate and JdbcTemplate takes the latter approach. Pass in the values as a java.util.List of primitive objects. This list will be used to insert the required placeholders and pass in the values during the statement execution.
Hope this can help you.

AFAIK, there is no standard support in JDBC for handling Collections as parameters. It would be great if you could just pass in a List and that would be expanded.
Spring's JDBC access supports passing collections as parameters. You could look at how this is done for inspiration on coding this securely.
See Auto-expanding collections as JDBC parameters
(The article first discusses Hibernate, then goes on to discuss JDBC.)

See my trial and It success,It is said that the list size has potential limitation.
List l = Arrays.asList(new Integer[]{12496,12497,12498,12499});
Map param = Collections.singletonMap("goodsid",l);
NamedParameterJdbcTemplate namedParameterJdbcTemplate = new NamedParameterJdbcTemplate(getJdbcTemplate().getDataSource());
String sql = "SELECT bg.goodsid FROM beiker_goods bg WHERE bg.goodsid in(:goodsid)";
List<Long> list = namedParameterJdbcTemplate.queryForList(sql, param2, Long.class);

There are different alternative approaches that we can use.
Execute Single Queries - slow and not recommended
Using Stored Procedure - database specific
Creating PreparedStatement Query dynamically - good performance but loose benefits of caching and needs recompilation
Using NULL in PreparedStatement Query - I think this is a good approach with optimal performance.
Check more details about these here.

sormula makes this simple (see Example 4):
ArrayList<Integer> partNumbers = new ArrayList<Integer>();
partNumbers.add(999);
partNumbers.add(777);
partNumbers.add(1234);
// set up
Database database = new Database(getConnection());
Table<Inventory> inventoryTable = database.getTable(Inventory.class);
// select operation for list "...WHERE PARTNUMBER IN (?, ?, ?)..."
for (Inventory inventory: inventoryTable.
selectAllWhere("partNumberIn", partNumbers))
{
System.out.println(inventory.getPartNumber());
}

One way i can think of is to use the java.sql.PreparedStatement and a bit of jury rigging
PreparedStatement preparedStmt = conn.prepareStatement("SELECT * FROM MYTABLE WHERE MYCOL in (?)");
... and then ...
preparedStmt.setString(1, [your stringged params]);
http://java.sun.com/docs/books/tutorial/jdbc/basics/prepared.html

how to overwrite using spring jdbctemplate batchupdate while inserting records?

Need to insert records using spring jdbctemplate batch update. while inserting if duplicate record is found, the record needs to be updated else inserted. how do i do that?
Below is my code.
Note:have not included exception handling.
result = jdbcTemplate.batchUpdate(
"insert ignore xxx set yy = ?, zz = ? where aa = ?",
new BatchPreparedStatementSetter() {
public void setValues(PreparedStatement ps, int i) throws SQLException {
ps.setDouble(1, Double.parseDouble(new JSONObject(jsonArray.get(i).toString()).get("aa").toString()));
ps.setDouble(2, Double.parseDouble(new JSONObject(jsonArray.get(i).toString()).get("bb").toString()));
ps.setString(3, new JSONObject(jsonArray.get(i).toString()).get("cc").toString());
}
public int getBatchSize() {
return jsonArray.length();
}
} );
}

You could use one of the following choices:
as #fbokovikov said you can use merge sql command.
you can check if the record is exist or not. In case of performance you can first get all the keys from db and then generate correct insert and update queries using those keys. In this scenario you should be aware of poor performance if you have big data in your table.
you can delete records first and then insert them all. This is very bad in performance. :-)
Hope that helps

Need to insert records using spring jdbctemplate batch update. while
inserting if duplicate record is found, the record needs to be updated
else inserted
For this purpose you should use standard SQL-2003 command merge.
In MySQL this command has following syntax:
INSERT...ON DUPLICATE KEY UPDATE

UPDATE PreparedStatement not updating MSSQL using JDBC

I am trying to update a MSSQL instance using JDBC using a prepared statement, I made a method to update any record in the table when given the column name, the value to update, and the updated value.
public void updateProjectOptions(int projectID, int number, String column){
try {
PreparedStatement ps = conn.prepareStatement("UPDATE cryptic.dbo.projects SET ? = ? WHERE project_id = ?");
int newNum = number+1;
System.out.println(projectID+" "+newNum+" "+column);
ps.setString(1, column);
ps.setInt(2, newNum);
ps.setInt(3, projectID);
int debug = ps.executeUpdate();
System.out.println("Rows affected: "+debug);
} catch (SQLException ex) {
Logger.getLogger(DAL.class.getName()).log(Level.SEVERE, null, ex);
}
}
The first print statement is printing out the correct values so I know the inputs are correct, and the second print statement is letting me know that 1 row is affected which is correct.
If I run the script inside of Management Studio the script runs fine and updates the table, but if I run the script from the java project nothing is updated and no errors are generated.
The db table in question has 4 columns: (int)project_id, (nvarchar)project_name, (int)num_bugs, (int)num_features
Can anyone help me out with getting this to work and/or spot whats wrong?

You can't bind a column name that way, only variables.
I would recommend that you close that PreparedStatement in method scope in a finally block. Your way is asking for trouble.
I would also call writing to System.out a very bad idea. I'd prefer returning the number of affected rows to the user.

Column names cannot be parameterized in prepared statements. You can parameterize only literal values like strings or numbers.

Use of getters in ResultSets

I am trying to write java code to access a table 'customer' with columns 'customer_id', 'email', 'deliverable', and 'create_date'
I have
Connection conn = DriverManager.getConnection(connectionUrl, connectionUser, connectionPassword);
Statement constat = conn.createStatement();
String query = "SELECT * FROM customer WHERE customer_id LIKE " + customerId;
ResultSet rtn = constat.executeQuery(query);
Customer cust = new Customer(rtn.getInt("customer_id"), rtn.getString("email"), rtn.getInt("deliverable"), rtn.getString("create_date"));
conn.close();
return cust;
I am receiving the error:
java.sql.SQLException: Before start of result set
As far as I can tell, my error is in the line where I am creating a new Customer object, but I cannot figure out what I am doing wrong. Can anyone offer me some help? Thanks!

You must always go to the next row by calling resultSet.next() (and checking it returns true), before accessing the data of the row:
Customer cust = null;
if (rtn.next()) {
cust = new Customer(rtn.getInt("customer_id"),
rtn.getString("email"),
rtn.getInt("deliverable"),
rtn.getString("create_date"));
}
Note that you should also
use prepared statements instead of String concatenation to avoid SQL injection attacks, and have more robust code
close the connections, statements and resultsets in a finally block, or use the try-with-resources construct if using Java 7
Read the JDBC tutorial

You should call ResultSet.first() to move the result to the first position. The result set is a programming convention not to retrieve the whole result of the query and keep in memory. As such, its interface is quite low level and you must explicit select the row via methods like first(), last() or next() (each returns true to check if the requested row index is in the set)

You need to add
rtn.next();
before you use the result set.
Usually this is done as
while (rtn.next()) {
<do something with the row>
}

Java, PreparedStatement, TransactSQL (MS SQL), last insert id

I insert some values into a database using a PreparedStatement, but it seems, that i cannot retrieve the last insert id in that case.
I try to use the same statement as i use for Statements (below) but it doent work. It says, that .executeQuery() cannot take arguments in this case.
In fact, i don't exactly need the last insert id, the number of affected rows will do, but how do i get that? I thought PreparedStatement's .executeUpdate() method would return the number of affected rows, but it apparently it does not.
Here is the method.
public static int getLastInsertId(Statement stmt) throws SQLException {
String sql = "SELECT SCOPE_IDENTITY() AS id";
ResultSet rs = stmt.executeQuery(sql);
int id = 0;
while (rs.next()) {
id = rs.getInt("id");
}
return id;
}
Thank you in advance.

A PreparedStatement's executeUpdate method DOES indeed return the number of affected rows...