如何在Java中的where in子句中的单个变量中执行具有多个值的SQL语句

Question

I have to execute below query through JDBC call

select primaryid from data where name in ("abc", adc", "anx");

Issue is inside in clause I have to pass 11000 strings . Can I use prepared statement here? Or any other solution any one can suggest. I dont want to execute the query for each record, as it is consuming time. I need to run this query in very less time.

I am reading the strings from an XML file using DOMParser. and I am using sql server db.

Answer 1

I'm just wondering why you would need to have a manual set of 11,000 items where you need to specify each item. It sounds like you need to bring the data into a staging table (surely it's not been selected from the UI..?), then join to that to get your desired resultset.

Answer 2

Using an IN clause with 11k literal values is a really bad idea - off the top of my head, I know one major RDBMS (Oracle) that doesn't support more than 1k values in the IN list.

What you can do instead:

• create some kind of (temporary) table T_NAMES to hold your names; if your RDBMS doesn't support "real" (session-specific) temporary tables, you'll have to add some kind of session ID
• fill this table with the names you're looking for
• modify your query to use the temporary table instead of the IN list: select primaryid from data where name in (select name from T_NAMES where session_id = ?session_id) or (probably even better) select primaryid from data join t_names on data.name = t_names.name and t_names.session_id = ?session_id (here, ?session_id denotes the bind variable used to pass your session id)

Answer 3

A prepared statement will need to know the number of arguments in advance - something along the lines of :

PreparedStatement stmt = conn.prepareStatement(
    "select id, name from users where id in (?, ?, ?)");
stmt.setInt(1);
stmt.setInt(2);
stmt.setInt(3);

11,000 is a large number of parameters. It may be easiest to use a 'batch' approach as described here (in summary - looping over your parameters, using a prepared statement each time)

Note - if your 11,000 strings are the result of an earlier database select, then the best approach is to write a stored procedure to do the whole calculation in the database (avoiding passing the 11,000 strings back and forth with your code)

Answer 4

You can merge all your parameter strings into one bitg string separating by ';' char

bigStrParameter=";abc;adc;anx;"

And use LOCATE to find substring.

select primaryid from data where LOCATE(concat(';',name,';'),?)>=0;