----- OCI program The basic structure OCI program includes the following components: 1. Initialize the OCI programming environment and thread 2. Assign the necessary handle (Handle) and data structure, establish connection with the server and user session 3 By performing data exchange with the database server on the database server, and performs the necessary data processing 4. Repeat the ready statement or make a new statement to be executed 5. Substant session and server connection 6. Release the handle This is just one The steps of the simple OCI program, the functionality of the program will vary. It takes more steps to operate multiple sessions, transactions, and OCI programs that use Objects. ------ The data structure handle of the OCI program and the description word belong to the opaque data structure defined in the OCI program, which can be directly assigned by a particular allocation operation, or some OCI functions implicitly allocated. Handle and description word stores information related to data, connection, or program behavior. Almost all OCI functions contain one or more handle parameters. Handle is a pointer to the storage area assigned to the OCI library. A handle can be used to store context or connection information (such as an environment or service context handle). Since the handle is managed by the link library instead of an application, it can simplify programming. Most OCI applications need to access information in the handle. This information can be accessed by using OCIATRTGET () and OCIATRRSET () these acquisitions or setting properties. The following is the OCI handle type were described, C type, handle type OCI handle type OCI environment handle OCIEnv OCI_HTYPE_ENV OCI error handle OCIError OCI_HTYPE_ERROR OCI service context handle OCISvcCtx OCI_HTYPE_SVCCTX OCI statement handle OCIStmt OCI_HTYPE_STMT OCI bind handle OCIBind OCI_HTYPE_BIND OCI define handle OCIDefine OCI_HTYPE_DEFINE OCI describe handle OCIDescribe OCI_HTYPE_DESCRIBE OCI server handle OCIServer OCI_HTYPE_SERVER OCI user session handle OCISession OCI_HTYPE_SESSION OCI transaction handle OCITrans OCI_HTYPE_TRANS OCI complex object retrieval (COR) handle OCIComplexObject OCI_HTYPE_COMPLEXOBJECT OCI thread handle OCIThreadHandle N / A OCI subscription handle OCISubscription OCI_HTYPE_SUBSCRIPTION OCI direct path context handle OCIDirPathCtx OCI_HTYPE_DIRPATH_CTX OCI direct path column array handle OCIDirPathColArray OCI_HTYPE_DIRPATH_COLUMN_ARRAY OCI direct path stream handle OCIDirPathStream OCI_HTYPE_DIRPATH_STREAM OCI process handle OCI_HTYPE_PROC
