How to Efficiently Use PreparedStatement with an IN Clause for Multiple Parameter Values?

Utilizing PreparedStatement with an IN Clause Parameter List

In JDBC, the PreparedStatement interface enables the execution of SQL queries with dynamically set parameter values. One common scenario involves utilizing an IN clause to retrieve data based on multiple values.

Query Syntax with an IN Clause

The following syntax demonstrates an example of a query using an IN clause:

connection.prepareStatement("Select * from test where field in (?)");

Handling Multiple Values

If the IN clause requires multiple values, there are two approaches to handle this situation:

1. Known List of Parameters:

• Construct a series of question marks ("?") in the query string, each representing a placeholder for a parameter value.
• For example:

var stmt = String.format("select * from test where field in (%s)",
                         values.stream()
                         .map(v -> "?")
                         .collect(Collectors.joining(", ")));

2. Unknown List of Parameters:

• Utilize a StringBuilder to dynamically generate the placeholder string.
• For each value, append a question mark and a comma.
• Remove the trailing comma before concatenating to the query string.
• For example:

StringBuilder builder = new StringBuilder();

for( int i = 0 ; i < values.size(); i++ ) {
    builder.append("?,");
}

String placeHolders =  builder.deleteCharAt( builder.length() -1 ).toString();
String stmt = "select * from test where field in ("+ placeHolders + ")";

Setting Parameter Values

Once the query string is prepared, set the parameter values using the PreparedStatement's setObject method. The index of the parameter should be updated for each value. For example:

int index = 1;
for( Object o : values ) {
   pstmt.setObject(  index++, o );
}

The above is the detailed content of How to Efficiently Use PreparedStatement with an IN Clause for Multiple Parameter Values?. For more information, please follow other related articles on the PHP Chinese website!