Use of object type converter (OTT) in Oracle call interface (OCI)

Ott is a very important tool in OCI to access object-type data. It maps object types or geometric objects in the database into structures in C language for OCI programs. In all operating systems that support Oracle, The OTT tool works as a command line. To use it, we must first make some preparations.

Set the ORACLE_HOME environment variable. my options are c: \ app \ zxg \ product \ 11.1.0 \ db_1.

In Windows command line mode, enter Ott and the following information appears,

 

Example of Ott usage method: first, create a type under the Scott user

Create type emp_t as object

(Name varchar2 (30 ),

Empno number,

Deptno number,

Hiredate date,

Salary number );

 

On the local machine, I run this program in the root directory of the D Drive. In the root directory of the D Drive, create the file demoin. TPY and write it into the file.

Case = lower

Type emp_t

And save. Enter the OTT command,

D: \> Ott userid = Scott/tiger intype = demoin. TPY outtype = demoout. TPY code = C hfile = demo. h initfile = demov. c

Specifically, use the username Scott and password tiger to connect to the database and convert the type definition in the input file demoin. TPY to the struct declaration in the C language. Output to the header file demo. H (struct definition in C) and demoout. TPY. The implementation file demov. C contains information about user-defined type conversion and initialization functions.

 

After executing this command, the demoout. TPY file generated by Ott is as follows:

Case = lower

Initfile = demov. c

Initfunc = demov

 

Type Scott. emp_t as emp_t

Version = "$8.0"

Hfile = demo. h

 

The contents of the header file demo. h generated by Ott are as follows:

# Ifndef demo_oracle

# Define demo_oracle

 

# Ifndef oci_oracle

# Include <OCI. h>

# Endif

 

Typedef ociref emp_t_ref;

 

Struct emp_t

{

Ocistring * Name;

Ocinumber empno;

Ocinumber deptno;

Ocidate hiredate;

Ocinumber salary;

};

Typedef struct emp_t;

 

Struct emp_t_ind

{

Ociind _ atomic;

Ociind name;

Ociind empno;

Ociind deptno;

Ociind hiredate;

Ociind salary;

};

Typedef struct emp_t_ind;

 

# Endif

 

The implementation file demov. c generated by Ott is as follows:

 

# Ifndef oci_oracle

# Include <OCI. h>

# Endif

 

Sword demov (ocienv * ENV, ocierror * ERR)

{

Sword status = ocitypevtinit (ENV, err );

If (status = oci_success)

Status = ocitypevtinsert (ENV, err,

(Unsigned char *) "Scott", 5,

(Unsigned char *) "emp_t", 5,

(Unsigned char *) "$8.0", 4 );

Return status;

}

 

Once the OTT type conversion is completed, the header file contains a struct definition of the corresponding type for each object type in the intype file, and a struct represents a Null Indicator of this type. For example, in the header file, the struct emp_t represents the object type emp_t, and a corresponding indicator struct emp_t_ind.

 

This is only for the C language. to convert it to the C ++ source file, you must enter a command similar to the following:

Ott userid = Scott/tiger intype = demoin. TPY outtype = demoout. TPY code = CPP hfile =
Sdogeometry. h cppfile = sdogeometry. cpp

After the input is correct, the following file is obtained.