![]() ![]() Method should be set to an acceptable value that you've chosen to represent a NULL. Use primitive data types and the ResultSet object's wasNull( ) method to test whether the primitive variable that received the value returned by the getXXX( ) ![]() Returned by the getXXX( ) method should be set to null. Use wrapper classes for primitive data types, and use the ResultSet object's wasNull( ) method to test whether the wrapper class variable that received the value ![]() So, to handle SQL NULL values in Java, there are three tactics you can use −Īvoid using getXXX( ) methods that return primitive data types. SQL's use of NULL values and Java's use of null are different concepts. When you run JDBCExample, it produces the following result − Now let us compile the above example as follows − Your task is to do step-wise operations as given below: 1. The class maps to the SQL DATE type, and the and classes map to the SQL TIME and SQL TIMESTAMP data types, respectively.įollowing example shows how the Date and Time classes format the standard Java date and time values to match the SQL data type requirements. You will be given four different variables of different data types: a (int), b (float), c (double), l (long), d ( byte). Each method can be used with column name or by its ordinal position. ResultSet object provides corresponding getXXX() method for each data type to retrieve column value. The methods, setObject() and updateObject(), enable you to map almost any Java type to a JDBC data type. The setXXX() and updateXXX() methods enable you to convert specific Java types to specific JDBC data types. The ResultSet object now has updateBLOB(), updateCLOB(), updateArray(), and updateRef() methods that enable you to directly manipulate the respective data on the server. JDBC 3.0 has enhanced support for BLOB, CLOB, ARRAY, and REF data types. The following table summarizes the default JDBC data type that the Java data type is converted to, when you call the setXXX() method of the PreparedStatement or CallableStatement object or the ResultSet.updateXXX() method. Default mappings were created to provide consistency between drivers. Method 1 (Writing our own sort) In below code, we have implemented Bubble Sort to sort the array. The idea here to solve this problem is to make a template. For example, a Java int is converted to an SQL INTEGER. The examples above show, we can have any data type elements present as an input and output will be in a sorted form of the input data. It uses a default mapping for most data types. The JDBC driver converts the Java data type to the appropriate JDBC type, before sending it to the database. ![]()
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