INFORMIX-4GL utilities (1) (1)

Setting Informix Environment Variables

I. Environment example
Variable Name Description
DBDELIMITER specifies the field delimiters used by dbload in the extract data file.
DBDATE specifies the date format (Y4MD/, MDY4-) to be used in the database -)
DBEDIT specifies the Text Editor (vi) to be used in the programmer Environment)
DBLANG specifies the storage directory of the message files used in the program
DBMONEY specifies the currency format to be used in DB
DBPATH specifies the search path for the database and other corresponding files
DBPRINT specifies the computer's print program
DBSRC specifies the search path for files in the program debugging phase
DBTEMP specifies the directory for storing temporary files
INFORMIXDIR specifies the directory for storing Informix files (/usr/informix)
INFORMIXSERVER specifies the name of the database server of Informixr
FORMDIR specifies the storage path of Informix screen format files
DBNLS specifies that Informix transmits Chinese characters (DBNLS = 2)
LANG specifies that Informix can display Chinese characters (LANG = english.8859)
ONCONFIG specifies the configuration file (onconfig. life) of Informix-Online)
PATH specifies the search PATH for Informix executable files
TERM specifies the terminal type of Informix (TERM = vt100)
TERMCAP specifies the terminal type file of Informixr

II. Environment example
. Profile (the environment variable must not contain spaces before and after the equal sign)
Stty-istrip-isig (preventing illegal user interruption)
INFORMIXDIR =/usr/informix
INFORMIXSERVER = ld4205020.tcp
ONCONFIG = onconfig. life
PATH = $ PATH: $ INFORMIXDIR/bin: $ HOME/form: $ HOME/prg
DBPATH =/u/cbps/form:/u/cbps/bin
FORMDIR =/u/cbps/form
DBDATE = Y4MD/
LANG = english_us.8859
DBLANG = english_us.8859
DBNLS = 2
TERMCAP =/usr/informix/etc/termcap
TERM = vt100
ExportINFORMIXDIRINFORMIXSERVERONCONFIGPATHDBPATHFORMDIRDBDATELANG
ExportDBLANGDBNLSTERMCAPTERM
Other Shell statements can be added to the environment variable setting file.

Introduction to Informix product lines and DB application development tools

I. Informix (EF Mei) Product Line introduction (three categories ):

1. Database Server (DatabaseServer)
①. ODS (Informix-OnlineDynemicServer) Online dynamic server, multi-clue, multi-performance DBserver (Database Server)
②. XPS (Informix-OnlineExtendedParallelServer) extends DSA to a loosely coupled or non-shared computing architecture and dynamically Scalable Architecture (DynemicScerableArchiterta), suitable for applications in large databases, parallel SQL operations.
③. IUS (Informix-UniversblServer)
It is designed to process rich and complex Data and uses Datablade module technology to store and retrieve rich multimedia Data and other complex insertion or object extension modules.

2. Application Development Tools
① Informix-NERERA is suitable for the C/S (Client/Server) mode of key businesses. It is an open and graphical object-oriented development environment. Slave → Client/ServerModel
②. Informix-4GL is suitable for all types of business of the dumb terminal operation mode, wide applicability, convenient development, good maintainability, powerful functions, no graphical functions, user interface is not friendly.
③. Informix-SQL conforms to international standard SQL language and is universal. It integrates DDL and DML. It is highly non-procedural and can be divided into two forms: embedded and interactive. It has data control and access functions.
④. Informix-ESQL/C embeds SQL into the C language to provide the target function library for implementing the SQL language, and uses the Host Program to complete an application process.

3. Connection tools
C4gl <*. 4gl *. c *. ec *. o>-c, o, s
Compiler → 4gl source program file compilation, connection generation target file or executable file
Esql <*. ec *. c *. o>-c, o
Compiler → esql source program file compilation, connection generation target file or executable file
Cc <*. c *. o>-c, o
Compile → C language source program file compilation, connection to generate the target file or executable file
Ii. StructuredQueryLanguage

1. Main Features of SQL (Structured Query Language): (RDBServer Relational Database Server)
①. Integration: DDL and DML are integrated.
②. Highly procedural: whattodo and nothowtodo are easy to use.
③ SQL interactive and SQL embedded formats are available.
2. SQL language classification:
①. DDL (Data Definition Language): used to create, modify, and delete the database base table view.
②. DML (data manipulation language): queries or adds, deletes, and modifies data in the database.
③. DCL (data control access language): controls the access permission root, authorization and revocation, cursor statements, dynamic management statements, data integrity statements, query optimization statements, and transaction processing statements.

Iii. DBMS utilities such as Stores7, Dbaccess, Isql, I4gl, and Upscol
1. $ dbaccessdemo7 [DBname] [withlog]
Choose → create an example DB slave → database name slave → No system logs by default

2. $ dbaccess
Choose → a dbms instance program bound to Informix-OnlineDBServer, which can be:
①. This tool can be used to create and delete databases.
②. Query various information in the database and edit the SQL statement.
③. Create, modify, and delete the base table of the database.
④. Add, delete, and modify the original records in the database.
⑤. Load data from the OS (operating system) file to the database.
6. Unload data from the database to an OS (operating system) file.
7. Create recycle permission.
You can use this tool to create, delete, and modify the Procedure process ).