How to Use in Clause with Preparedstatement in Postgresql

Conditions in prepared statements in postgres

This query will work for you.

select * from users where
  case
    when coalesce($1, '') = '' then true 
    else (name ~ $1)
  end;

PreparedStatement IN clause alternatives?

An analysis of the various options available, and the pros and cons of each is available in Jeanne Boyarsky's Batching Select Statements in JDBC entry on JavaRanch Journal.

The suggested options are:

• Prepare SELECT my_column FROM my_table WHERE search_column = ?, execute it for each value and UNION the results client-side. Requires only one prepared statement. Slow and painful.
• Prepare SELECT my_column FROM my_table WHERE search_column IN (?,?,?) and execute it. Requires one prepared statement per size-of-IN-list. Fast and obvious.
• Prepare SELECT my_column FROM my_table WHERE search_column = ? ; SELECT my_column FROM my_table WHERE search_column = ? ; ... and execute it. [Or use UNION ALL in place of those semicolons. --ed] Requires one prepared statement per size-of-IN-list. Stupidly slow, strictly worse than WHERE search_column IN (?,?,?), so I don't know why the blogger even suggested it.
• Use a stored procedure to construct the result set.
• Prepare N different size-of-IN-list queries; say, with 2, 10, and 50 values. To search for an IN-list with 6 different values, populate the size-10 query so that it looks like SELECT my_column FROM my_table WHERE search_column IN (1,2,3,4,5,6,6,6,6,6). Any decent server will optimize out the duplicate values before running the query.

None of these options are ideal.

The best option if you are using JDBC4 and a server that supports x = ANY(y), is to use PreparedStatement.setArray as described in Boris's anwser.

There doesn't seem to be any way to make setArray work with IN-lists, though.

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Sometimes SQL statements are loaded at runtime (e.g., from a properties file) but require a variable number of parameters. In such cases, first define the query:

query=SELECT * FROM table t WHERE t.column IN (?)

Next, load the query. Then determine the number of parameters prior to running it. Once the parameter count is known, run:

sql = any( sql, count );

For example:

/**
 * Converts a SQL statement containing exactly one IN clause to an IN clause
 * using multiple comma-delimited parameters.
 *
 * @param sql The SQL statement string with one IN clause.
 * @param params The number of parameters the SQL statement requires.
 * @return The SQL statement with (?) replaced with multiple parameter
 * placeholders.
 */
public static String any(String sql, final int params) {
    // Create a comma-delimited list based on the number of parameters.
    final StringBuilder sb = new StringBuilder(
        String.join(", ", Collections.nCopies(possibleValue.size(), "?")));

    // For more than 1 parameter, replace the single parameter with
    // multiple parameter placeholders.
    if (sb.length() > 1) {
        sql = sql.replace("(?)", "(" + sb + ")");
    }

    // Return the modified comma-delimited list of parameters.
    return sql;
}

For certain databases where passing an array via the JDBC 4 specification is unsupported, this method can facilitate transforming the slow = ? into the faster IN (?) clause condition, which can then be expanded by calling the any method.

How to use prepared statements in DO statements?

You cannot use a DO statement as a prepared statement.

I recommend that you use two statements:

• one get the three results that you need to determine if there is an error condition

• one to run the INSERT statement

The second of these would be a regular prepared statement.

It seems to me that you are mixing up transactions and BEGIN ... END blocks in PL/pgSQL.

PreparedStatement with list of parameters in a IN clause

What I do is to add a "?" for each possible value.

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

Alternative using StringBuilder (which was the original answer 10+ years ago)

List values = ... 
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 + ")";
PreparedStatement pstmt = ... 

And then happily set the params

int index = 1;
for( Object o : values ) {
   pstmt.setObject(  index++, o ); // or whatever it applies 
}

Postgres SQL in clause and setArray()

When your database field is of type array, then you can use the PreparedStatement.setArray() to send an array to the query. But, in your case, it's not really an array, rather is a variable no of arguments, and you can't do that. i.e.

PreparedStatement ptmt =  connection.prepareStatement("select * from foo where id in (?)");

can take only one parameter. If you want 3 parameters to be passed, you have to do

PreparedStatement ptmt =  connection.prepareStatement("select * from foo where id in (?, ?, ?)");

And do ptmt.setString(n, "String") thrice.

If your no of arguments aren't constant, then construct the query dynamically, although, you loose the efficiency.

prepared statement - using parameter to specify table name

It is not possible. The prepare statement is persistent execution plan - and execution plan contains pined source of data - so tables, column names cannot be mutable there.

When you change table, columns, then you change the semantic of query - you will got different execution plan and then this behave is not possible in prepared statements. The main use case of prepared statements is reusing of execution plans - plan once, execute more. But there are some principal limits - only some parameters can be changed.

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