Binary to decimal in java api
Also, the String class makes conversions between String and char easy: There is a method for converting a String object to a char and also a constructor for turning a char into a String object. Thus, when a CHAR n field is retrieved from the database, the driver will convert it to a Java String object of length n , which may include some padding spaces at the end. Note that the method getUnicodeStream has been deprecated. The SQL3 CLOB data type, which is described later in this chapter, provides an alternate means of representing large amounts of character data.
Unfortunately, the use of these various BINARY types has not been standardized and support varies considerably among the major databases. It takes a parameter that specifies the number of binary bytes. It takes a parameter that specifies the maximum number of binary bytes. All the major databases support some kind of very large variable length binary type supporting up to at least a gigabyte of data, but the SQL type names vary. Since it is possible to read and write SQL statements correctly without knowing the exact BINARY data type that was expected, there is no need for programmers writing code in the Java programming language to distinguish among them.
The SQL3 BLOB data type, which is described later in this chapter, provides an alternate means of representing large amounts of binary data. In practice the SQL BIGINT type is not yet currently implemented by any of the major databases, and we recommend that its use be avoided in code that is intended to be portable.
FLOAT represents a "double precision" floating point number that supports 15 digits of mantissa. They both represent fixed-precision decimal values. These SQL types take precision and scale parameters. The precision is the total number of decimal digits supported, and the scale is the number of decimal digits after the decimal point. For most DBMSs, the scale is less than or equal to the precision. So for example, the value " BigDecimal type provides math operations to allow BigDecimal types to be added, subtracted, multiplied, and divided with other BigDecimal types, with integer types, and with floating point types.
It is also possible to retrieve these SQL types as any of the Java numeric types. Because the standard Java class java. Date to correspond to the SQL types. All three of the JDBC time-related classes are subclasses of java. Date , and as such, they can be used where a java. For example, internationalization methods take a java. Date object as an argument, so they can be passed instances of any of the JDBC time-related classes.
A JDBC Timestamp object has its parent's date and time components and also a separate nanoseconds component. Timestamp object is used where a java.
Date object is expected, the nanoseconds component is lost. However, since a j ava. Date object is stored with a precision of one millisecond, it is possible to maintain this degree of precision when converting a java.
Timestamp object to a java. This is done by converting the nanoseconds in the nanoseconds component to whole milliseconds by dividing the number of nanoseconds by 1,, and then adding the result to the java. Up to , nanoseconds may be lost in this conversion, but the resulting java. Date object will be accurate to within one millisecond. The following code fragment is an example of converting a java. Date object that is accurate to within one millisecond. New methods in the JDBC 2.
The time zone information is included in a java. Calendar object that is passed to new versions of the methods for getting and setting Date , Time , and Timestamp values. When no time zone is specified, the driver uses the time zone of the virtual machine running the application when it calculates a date, time, or timestamp. This section describes each data type briefly; more complete information on each type can be found in the reference chapter for the corresponding interface.
The new data types in the JDBC 2. In general, they are more like objects; in fact, two of the new data types are UDTs that can optionally be custom mapped to classes in the Java programming language. Despite their advanced nature, all of the new data types in the JDBC 2.
For example, they can be used as column values in database tables, and they can be retrieved and stored using the appropriate getXXX and setXXX methods. If a driver follows the standard implementation, a Blob object logically points to the BLOB value on the server rather than containing its binary data, greatly improving efficiency.
Internally, a byte array is used. Serialization and deserialization is done on the client side only. Deserialization is only done when getObject is called. Java operations cannot be executed inside the database engine for security reasons. The maximum precision is Integer. The whole text is loaded into memory when using this data type. For large text data CLOB should be used; see there for details.
Stored in mixed case. This type is supported for compatibility with other databases and older applications. The whole text is kept in memory when using this data type. InputStream is also supported. Reader is also supported. This is a bit value. To store values, use PreparedStatement. Please note that using an index on randomly generated data will result on poor performance once there are millions of rows in a table.
The reason is that the cache behavior is very bad with randomly distributed data. This is a problem for any database system. An array of values. Implicit conversion from Double to BigDecimal. Tests whether the argument that is a reference to the receiver object this. The eq method implements an equivalence relation on non-null instances of AnyRef , and has three additional properties:.
When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. See also equals in scala. Constructs a BigDecimal that exactly represents the number specified in base 10 in a character array.
Constructs a BigDecimal that exactly represents the number specified in a String. Constructs a BigDecimal that exactly represents a Long. Note that all creation methods for BigDecimal that do not take a MathContext represent a Long ; this is equivalent to apply , valueOf , etc.. Constructs a BigDecimal that exactly represents a BigInt. Constructs a BigDecimal by fully expanding the binary fraction contained by Double value d , adjusting the precision as necessary.
The precision is the default for BigDecimal or enough to represent the java. BigDecimal exactly, whichever is greater. Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.
The hashCode method for reference types. See hashCode in scala. Test whether the dynamic type of the receiver object is T0. Note that the result of the test is modulo Scala's erasure semantics. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
Implicit conversion from java. Wakes up a single thread that is waiting on the receiver object's monitor. Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, " ", and the object's hashcode in hexadecimal. BigDecimal but actually doesn't. Use new BigDecimal bd, mc instead for no rounding, or BigDecimal.