【雞】丁酉年己酉月庚戌日 / 八月初三日
Wednesday September 20, 2017

Databases

Are your Chinese characters showing up as question marks ?
Then do the following checks :
  • Check which encoding/character set is used to post data to the database or table
  • Check the default encoding/character set of the database
  • Check the encoding/character set of the table
  • Check the encoding/character set of the program that you use to retreive data from the database/table
  • Check the encoding/character set that is used to display the data that you retreived
They should be all the same, if not, that may be the cause why your Chinese characters are displayed as question marks ('????') instead of Chinese characters.

Since in most of the times other program performs queries at the database we have two sides, the database-server and the client. So be aware that one has to know which encoding/characterset is used on both sides.

Data is usually stored in the form of records. Each record consists of a collection of related data values or items, where each value is formed of one or more bytes and corresponds to a particular fied of the record. Records usually describe entities and their attributes. A collection of field names and their corresponding data types constitutes a record type or record format definitions. A data type associated with each field specifies the type of values a field can take.
A file is a sequence of records. In many cases, all records in a file are of the same record type. If every record in the file has exactly the same size (in bytes), the file is said to be made up of fixed-length records. If diferent records in the file have different sizes, the file is said to be made up of variable-length records. A file may have variable-length records for several reasons : (1) The file records are the same record type, but one or mare fields are of varying siwe (variable length fields). (2) The file records are of the same record type, but one or more of the fields may have multiple values for individual records; such a field is called a repeating field an a group of values for the field is often called a repeating group. (3) The file records are of the same records are of the same record type, but one or more fields are optional; that is, they may have values for some but not all of the fire records (optional fields). (4) The file contains records of different records types and hence of varying size (mixed file). This would occur if related records of different types were clustered (placed together) on disk blocks.

[ < back ] - [ home ]