C Applications. This chapter describes how you can use the ProCC Precompiler to precompile your C embedded SQL application, and how ProC generates C compatible code. This chapter contains the following topics Understanding C Support. To understand how ProC supports C, you must understand the basic functional capabilities of ProC. In particular, you must be aware of how ProC differs from Pro Version 1. The basic capabilities of ProC are Full C preprocessor support. You can use define, include, ifdef, and other preprocessor directives in your ProC program, to handle constructs that the precompiler itself must process. Use of native C structures as host variables, including the ability to pass structs or pointers to structs as host variables to functions, and write functions that return host structures or struct pointers. To support its C preprocessor capabilities and to enable host variables to be declared outside a special Declare Section, ProC incorporates a complete C parser. The ProC parser is a C parser it cannot parse C code. This means that for C support, you must be able to disable the C parser, or at least partially disable it. To disable the C parser, the ProC Precompiler includes command line options to give you control over the extent of C parsing that ProC performs on your source code. No Special Macro Processing. Using C with ProC does not require any special preprocessing or special macro processors that are external to ProC. There is no need to run a macro processor on the output of the precompiler to achieve C compatibility. If you are a user of a release of ProC Precompiler before this one, and you did use macro processors on the precompiler output, you should be able to precompile your C applications using ProC with no changes to your code. Precompiling for CTo control precompilation so that it accommodates C, there are four considerations Code emission by the precompiler. Parsing capability. The output filename extension. The location of system header files. Code Generation. You must be able to specify what kind of code, C compatible code or C compatible code, the precompiler generates. ProC by default generates C code. C is not a perfect superset of C. Some changes are required in generated code so that it can be compiled by a C compiler. For example, in addition to emitting your application code, the precompiler interposes calls to its runtime library, SQLLIB. The functions in SQLLIB are C functions. There is no special C version of SQLLIB. For this reason, if you want to compile the generated code using a C compiler, ProC must declare the functions called in SQLLIB as C functions. For C output, the precompiler would generate a prototype such as. But for C compatible code, the precompiler must generate. You control the kind of code ProC generates using the precompiler option CODE. HR0cDovL2Jsb2cuY3Nkbi5uZXQvdG90b3R1enVvcXVhbg==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast' alt='Sqlca.H File' title='Sqlca.H File' />There are three values for this option CPP, KRC, and ANSIC. The differences between these options can be illustrated by considering how the declaration of the SQLLIB function sqlora differs among the three values for the CODE option. K R C. void sqloraunsigned long void ANSI C. C CPP. When you specify CODECPP, the precompiler Generates C compilable code. Gives the output file a platform specific file extension suffix, such as. DawRKkBJ24k/UQpedN6lkfI/AAAAAAAABS4/2fybER3GK9g/s1600/shrink+SQL+Server+Log+Data+Files.png' alt='Sqlca.H File' title='Sqlca.H File' />The below is a sample PRO make file and program that calls an Oracle PLSQL block that maymay not have PLSQL Stored Procedures in it. C Applications. This chapter describes how you can use the ProC Precompiler to precompile your C embedded SQL application, and how ProC generates C. The method above works very efficiently if the entire name of a file is known, but sometimes only part of the name may be known or searching for. LOBs. This chapter describes the support provided by embedded SQL statements for the LOB Large Object datatypes. The four types of LOBs are introduced and. Preprocessor Directives The CC preprocessor directives that work with Pro are include and if. Pro does not recognize define. For example, the following code. Introduction. Embedded SQL is a method of combining the computing power of a highlevel language like CC and the database manipulation capabilities of SQL. CCOracleNUMBER. C or. You can override this by using the CPPSUFFIX option. Causes the value of the PARSE option to default to PARTIAL. You can also specify PARSENONE. If you specify PARSEFULL, an error is issued at precompile time. Allows the use of the C style Comments in your code. This style of Commenting is also permitted inside SQL statements and PLSQL blocks when CODECPP. ProC recognizes SQL optimizer hints that begin with. Requires that header files generated by OTT Object Type Translator must be included inside a declare section. See Also CODE for information about the KRC and ANSIC values for the CODE option. Parsing Code. You must be able to control the effect of the ProC C parser on your code. You do this by using the PARSE precompiler option, which controls how the precompilers C parser treats your code. The values and effects of the PARSE option are Table 1. Values and Effects of the PARSE Option. Values. Effects. PARSENONEThe value NONE has the following effects C preprocessor directives are understood only inside a declare section. You must declare all host variables inside a Declare Section. Precompiler release 1. PARSEPARTIALThe value PARTIAL has the following effects All preprocessor directives are understood. You must declare all host variables inside a Declare Section. This option value is the default if CODECPPPARSEFULLThe value FULL has the following effects The precompiler C parser runs on your code. All Preprocessor directives are understood. You can declare host variables at any place that they can be declared legally in C. This option value is the default if the value of the CODE option is anything other than CPP. It is an error to specify PARSEFULL when CODECPP. To generate C compatible code, the PARSE option must be either NONE or PARTIAL. If PARSEFULL, the C parser runs, and it does not understand C constructs in your code, such as classes. Output Filename Extension. Final Cut Pro 7 Serial Number. Most C compilers expect a default extension of. Different C compilers, however, can expect different filename extensions. The CPPSUFFIX option provides the ability to specify the filename extension that the precompiler generates. The value of this option is a string, without the quotes or the period. For example, CPPSUFFIXcc, or CPPSUFFIXC. System Header Files. ProC searches for standard system header files, such as stdio. ProC does not search for header files with extensions such as hpp or h. For example, on almost all UNIX systems, the file stdio. But a C compiler has its own version of stdio. When you are precompiling for C, you must use the SYSINCLUDE precompiler option to specify the directory paths that ProC searches to look for system header files. For example. SYSINCLUDEusrlangSC2. SC2. 1. 1include. Use the INCLUDE precompiler option to specify the location of non system header files. The directories specified by the SYSINCLUDE option are searched before directories specified by the INCLUDE option. See also INCLUDE. If PARSENONE, the values specified in SYSINCLUDE and INCLUDE for system files are not relevant, since there is no need for ProC to include system header files. You can, of course, still include ProC specific headers, such sqlca. EXEC SQL INCLUDE statement. Example Programs. This section includes three example ProC programs that include C constructs. Each of these programs is available on line, in your demo directory. Prompts the user for an employee number, then queries the. Uses indicator variables in an indicator struct to. Ati Radeon Xpress 200 Series Driver For Windows 8 more. NULL. include lt iostream. Parsepartial by default when codecpp. UNAMELEN 2. 0. PWDLEN 4. Declare section is required when CODECPP or. PARSEPARTIALNONE or both. EXEC SQL BEGIN DECLARE SECTION. VARCHAR usernameUNAMELEN VARCHAR is an ORACLE pseudotype. PWDLEN can be in lower case also. Define a host structure for the output values. SELECT statement. VARCHAR empnameUNAMELEN. Define an indicator struct to correspond to the. LOBs. This chapter describes the support provided by embedded SQL statements for the LOB Large Object datatypes. The four types of LOBs are introduced and compared to the older LONG and LONG RAW datatypes. The embedded SQL interface in ProC is shown to provide similar functionality to that of the Oracle Call Interface API and the PLSQL language. The LOB statements and their options and host variables are presented. Lastly, examples of ProC programs using the LOB interface are presented as simple illustrations of usage. What are LOBs Use LOB large object columns to store large amounts of data maximum size is 4 Gigabytes such as ASCII text, National Character text, files in various graphics formats, and sound wave forms. Internal LOBs. Internal LOBs BLOBs, CLOBs, NCLOBs are stored in database table spaces and have transactional support Commit, Rollback, and so on. BLOBs Binary LOBs store unstructured binary also called raw data, such as video clips. CLOBs Character LOBs store large blocks of character data from the database character set. NCLOBs National Character LOBs store large blocks of character data from the National Character Set. External LOBs. External LOBs are operating system files outside the database tablespaces, that have no transactional support from the database server. BFILEs Binary Files store data in external binary files. A BFILE can be in GIF, JPEG, MPEG, MPEG2, text, or other formats. Security for BFILEs. The DIRECTORY object is used to access and use BFILEs. The DIRECTORY is a logical alias name stored in the server for the actual physical directory in the server file system containing the file. Users are permitted to access the file only if granted access privilege on the DIRECTORY object. The DDL data definition language SQL statements CREATE, REPLACE, ALTER, and DROP are used with DIRECTORY database objects. The DML Data Management Language SQL statements are used to GRANT and REVOKE the READ system and object privileges on DIRECTORY objects. A example CREATE DIRECTORY directive is. EXEC SQL CREATE OR REPLACE DIRECTORY Mydir AS usrhomemydir. Other users or roles can read the directory only if you grant them permission with a DML Data Manipulation Language statement, such as GRANT. For example, to allow user scott to read BFILES in directory usrhomemydir. EXEC SQL GRANT READ ON DIRECTORY Mydir TO scott. Up to 1. 0 BFILES can be opened simultaneously in one session. This default value can be changed by setting the SESSIONMAXOPENFILES parameter. See Oracle Database Advanced Application Developers Guide for more details on DIRECTORY objects and BFILE security. See Oracle Database SQL Language Reference for more details on the GRANT command. LOBs versus LONG and LONG RAWLOBs are different from the older LONG and LONG RAW datatypes in many ways. The maximum size of a LOB is 4 Gigabytes versus 2 Gigabytes for LONG and LONG RAW. You can use random as well as sequential access methods on LOBs you can only use sequential access methods on LONG and LONG RAW. LOBs except NCLOBs can be attributes of an object type that you define. Tables can have multiple LOB columns, but can have only one LONG or LONG RAW column. Migration of existing LONG and LONG Raw attributes to LOBs is recommended by Oracle. Oracle plans to end support of LONG and LONG RAW in future releases. See Oracle. 9i Database Migration for more information on migration. LOB Locators. A LOB locator points to the actual LOB contents. The locator is returned when you retrieve the LOB, not the LOBs contents. LOB locators cannot be saved in one transaction or session and used again in a later transaction or session. Temporary LOBs. You can create temporary LOBs, that are like local variables, to assist your use of database LOBs. Temporary LOBs are not associated with any table, are only accessible by their creator, have locators which is how they are accessed, and are deleted when a session ends. There is no support for temporary BFILES. Temporary LOBs are only permitted to be input variables IN values in the WHERE clauses of INSERT, UPDATE, or DELETE statements. They are also permitted as values inserted by an INSERT statement, or a value in the SET clause of an UPDATE statement. Temporary LOBs have no transactional support from the database server, which means that you cannot do COMMITS or ROLLBACKs on them. Temporary LOB locators can span transactions. They also are deleted when the server abnormally terminates, and when an error is returned from a database SQL operation. LOB Buffering Subsystem. The LBS LOB Buffering Subsystem is an area of user memory provided for use as a buffer for one or more LOBs in the clients address space. Buffering has these advantages, especially for applications on a client that does many small reads and writes to specific regions of the LOB The LBS reduces round trips to the server because you fill the buffer with multiple readswrites to the LOBs, then write to the server when a FLUSH directive is executed. Buffering also reduces the total number of LOB updates on the server. This creates better LOB performance and saves disk space. Oracle provides a simple buffer subsystem not a cache. Oracle does not guarantee that the contents of a buffer are always synchronized with the server LOB value. Use the FLUSH statement to actually write updates in the server LOB. Buffered readwrite of a LOB are performed through its locator. A locator enabled for buffering provides a consistent read version of the LOB until you perform a write through that locator. After being used for a buffered WRITE, a locator becomes an updated locator and provides access to the latest LOB version as seen through the buffering subsystem. All further buffered WRITEs to the LOB can only be done through this updated locator. Transactions involving buffered LOB operations cannot migrate across user sessions. The LBS is managed by the user, who is responsible for updating server LOB values by using FLUSH statements to update them. It is single user and single threaded. Use ROLLBACK and SAVEPOINT actions to guarantee correctness in the server LOBs. Transactional support for buffered LOB operations is not guaranteed by Oracle. To ensure transactional semantics for buffered LOB updates, you must maintain logical savepoints to perform a rollback in the event of an error. For more information on the LBS, see Oracle Database Advanced Application Developers Guide. How to Use LOBs in Your Program. This section describes some of the important programming issues related to the use of LOBs in your ProC application. Three Ways to Access LOBs. The three methods available to access LOBs in ProC are The DBMSLOB package inside PLSQL blocks. OCI Oracle Call Interface function calls. Embedded SQL statements. The SQL statements are designed to give users a functional equivalent to the PLSQL interface while avoiding the complexity of the OCI interface. The following table compares LOB access by OCI function calls in ProC, PLSQL, and embedded SQL statements in ProC. Empty boxes indicate missing functionality. Table 1. 6 1 LOB Access Methods. OCI PLSQLProC Embedded SQL COMPARE INSTR SUBSTR OCILob. Append. APPENDAPPENDOCILob. Assign ASSIGNOCILob. Char. Set. Form OCIChar. Set. Id OCILob. Close. CLOSECLOSEOCILob. Copy. COPYCOPYOCILob. Create. Temporary. CREATETEMPORARYCREATE TEMPORARYOCILob. Disable. Buffering DISABLE BUFFERINGOCILob.