How do I write a Delete SQL Statement in Java for Tables with composite key?

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I'm 99% this question has been answered somewhere, but I can't seem to find what I'm looking for. So far, I've been writing my sql statement to delete a row from a table in java like this (this for a table called crime where the primary key is called CrimeId. The CrimeId is taken from the UI)

private DatabaseAPI db;
PreparedStatement st=db.connection.prepareStatement("DELETE FROM crime WHERE CrimeId = '"+Integer.parseInt(txtCrimeId.getText())+"';");

How would I write the where statement for a composite key? Like, for a table called charges in which the key is both CrimeID and CriminalID?

Something like below:

PreparedStatement st=db.connection.prepareStatement(
  "DELETE FROM crime WHERE CrimeId = ? AND CriminalID = ?" );
st.setInt(1, Integer.parseInt(txtCrimeId.getText() );
st.setInt( 2, Integer.parseInt(txtCriminaId.getText());

How do I write a Delete SQL Statement in Java for Tables with , SQL composite key with sql, tutorial, examples, insert, update, delete, select, join, database, table, join. A composite key is a combination of two or more columns in a table that can be used to Columns that make up the composite key can be of different data types. SQL Let's see the Syntax for the select top statement:. Let's see the Syntax for the SQL DELETE statement: DELETE FROM table_name [WHERE condition]; Here table_name is the table which has to be deleted. The WHERE clause in SQL DELETE statement is optional here.

DELETE FROM charges WHERE CrimeId = '____' AND CriminalID = '____' ;

Is this what you were looking for?

SQL COMPOSITE KEY, Please execute below query in SQL to create a table with COMPOSITE KEY i.e. PRIMARY KEY constraint on multiple columns. CREATE TABLE student (  To delete one or more rows of a database table from a Java program, you use the following steps: First, create a database connection to the SQLite database. Next, prepare the DELETE statement. In case you want the statement takes parameters, you use the question mark (?) placeholder inside the statement.

You need to use AND. With AND you combine to conditions.

Read this for more information

So then your code looks like

DELETE FROM charges WHERE CrimeId = 'YourCrimeID' AND CriminalID = 'YourCriminalID' ;

Just replace YourCriminalID and YourCrimeID.

SQL - PRIMARY KEY & COMPOSITE KEY, We can remove composite PRIMARY KEY constraint from multiple columns table by using DROP keyword along with ALTER TABLE statement. SQL DELETE statement is used to remove existing records in a table. We can use the WHERE clause with the DELETE query to delete the selected rows; otherwise, all the records would be eliminated. We have already seen the create table , insert row , update row , and now we will see how to remove or delete the row from the SQL table.

I believe next code should work for you

PreparedStatement st=db.connection.prepareStatement("DELETE FROM crime WHERE CrimeId = ? and CriminalID = ?");
st.setInt(1, Integer.parseInt(txtCrimeId.getText()));
st.setInt(2, Integer.parseInt(txtCriminalID.getText()));
st.executeUpdate();

How can we remove composite PRIMARY KEY constraint applied , SQL - Primary Key - A primary key is a field in a table which uniquely identifies each row/record in a database table. When multiple fields are used as a primary key, they are called a composite key. NOTE − If you use the ALTER TABLE statement to add a primary key, the primary key column(s) Delete Primary Key. I'm writing custom Oracle queries to delete data from child tables in order to avoid foreign key constraint as part of a utility to clean up test data. Let's say I've two tables - Table 1 (PK - (id1,id2)) and Table 2 (FK -(id3,id4)), where id1,id2,id3,id4 are all of type Number. Table 2 has a composite foreign key constraint on Table 1's

SQL - Primary Key, In the table above, we are creating the primary key using two columns – employee_no and employee_phn. Post-execution of the above query check the table  SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL Joins SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL

SQL Composite Key, Note: If you use the ALTER TABLE statement to add a primary key, the primary key column(s) must already have been declared to not contain NULL values (​when  SQL Composite Key. A composite key is a combination of two or more columns in a table that can be used to uniquely identify each row in the table when the columns are combined uniqueness is guaranteed, but when it taken individually it does not guarantee uniqueness.

SQL PRIMARY KEY Constraint, For detailed syntax, check MySQL manual "SQL Statement Syntax" TABLE tableName DROP FOREIGN KEY constraintName SHOW CREATE Let's call our database " southwind " (inspired from Microsoft's Northwind Trader sample database). 2.1 Creating and Deleting a Database - CREATE DATABASE and DROP  Let's say I have a table with a two-part composite key, and 4 records, like the following: KEY_PART_1 KEY_PART_2 A 1 B 1 C 2 C 3 I want to write some dynamic SQL to select only the records B,1 and C,2 using a "WHERE IN" clause, without selecting A,1 or C,3. Is there some way to do this without a temp table?

Comments
  • Use a where clause with and to combine multiple constraints. Why are you using prepared statements if you still concatenate values instead of binding them?