isqltcl-4.0.readme

来自「TCL的数据库处理支撑库及一些示例」· README 代码 · 共 410 行 · 第 1/2 页

                If type is 0, then the output sqlda is used.
                This number reflects the number of columns fetched from the
                dynamic query or the number of bind variables specified.
            char **sql_sqlda(int fd, int type, int elnum, int *numvalues)
                Returns array of character pointers (the number of such
                pointers is set in numvalues) for the sqlda element elnum.
                This contains information like the column name, type,
                value etc.
                type is the same as in sql_sqld
                elnum varies from 0 to sql_sqld(int fd, int type)
            int sql_finish()
                Closes the database opened earlier with sql_database
                Returns 0 on success, < 0 on failure
            char *sql_getdatabase()
                Gets the database name opened with sql_database

            All the C calls above should ensure that the fd is valid
            before it proceeds.

    COMPILING TCL
            To add support to TCL, two files have been provided
            1) sqlinf.ec  - code containing C calls to database
            2) tclsql.c   - code for wrappers around sqlinf.ec calls
                            which adds SQL support to TCL.
            Copy these files into the tcl distribution directory
            Users who want SQL support in TCL should add the call
                isql_init(interp) in tclAppInit.c (for tcl versions >= 7)
                or in their main.c 
            Compile sqlinf.ec with c4gl
                c4gl -c sqlinf.ec
            Add the file tclsql.o in the Makefile (to the GENERIC_OBJS define)
            Do a make with
                make CC=c4gl
            Use c4gl if you are using Informix 4 or greater since it does a
            better job of freeing cursors (in my opinion). Use esql if you
            do not have c4gl.

    COMPILING TK
            Users who want SQL support in TK should add the call
                isql_init(interp) in main.c or tkAppInit.c
            and link the wish interpreter again with
                make CC=c4gl.


    EXAMPLES

#ifdef TEST
main() {
    int fd, ret;

    sql_database("test");

    {
        char *argv[] = { "A%"};
        fd = sql_open("select emp_name from employee where emp_name like ?",
                        1, argv);
        ret = 0;
        while (ret == 0) {
            ret = sql_fetch(fd);
            if (ret == 0) sql_print(fd);
        }
    }

    {
        char **argv;
        sql_reopen(fd);
        sql_fetch(fd);
        argv = sql_values(fd, &ret, 0);
        if (!argv) printf("No values for fd%d\n", fd);
        else {
            int i;
            for (i = 0; i < ret; i++)
                printf("Value %d is (%s)\n", i, argv[i]);
        }
    }

    {
        char *argv[] = { "19"};
        if (sql_exists("employee", "emp_name", 0, 0)==0)
            printf("At least 1 employee exists\n");
        if (sql_exists("employee", "emp_name", "JOLLY'GOOD", 0)==0)
            printf("Employee JOLLY'GOOD exists\n");
        if (sql_exists("employee", "emp_name", 0, "emp_name matches 'A*'")==0)
            printf("Employee matching A* exists\n");
        if (sql_run("set lock mode to wait", 0, 0) == 0)
            printf("Successful lock mode\n");
        if (sql_run("update employee set salary = ?", 1, argv) == 0)
            printf("Successful update \n");
    }
}
#endif

    CONCLUSIONS

        I have posted the archived file isqltcl.tar.Z to
        harbor.ecn.purdue.edu. It should be available there soon.
        The command
            zcat isqltcl.tar.Z | tar xvf -
        will create the following files in the current directory
            sqlinf.ec
            tclsql.c
            readme.sql (this document)
        Follow the instructions provided earlier to compile it.

        If you have any suggestions or comments,
        please write [e-mail] (It may take some time for me to
        respond in the next two weeks since I will be relocating).

Informix SQL TCL - Release 2.1 fixed coredumps and new feature
--------------------------------------------------------------

    The sql close routine was freeing the descriptor which
    was allocated by describe. Now you may use esql or c4gl
    to compile the file.

    sql reopen now accepts bind parameters. Thus, the overhead of
    prepare,describe etc. in sql open is avoided.

    for e.g.

    sql database "db"
    set fd [sql open "select * from employee where emp_name = ?" "ABC"]
    puts stdout [sql fetch $fd]
    sql reopen $fd "XYZ"
    puts stdout [sql fetch $fd]

    I have uploaded the file isqltcl.tar.Z (containing
    readme.sql, sqlinf.ec and tclsql.c) to harbor.ecn.pudue.edu.
    It should be available there soon.

    If you have any suggestions or comments (or any problems),
    please write [e-mail]

Informix SQL TCL - Release 3.0 - support for BLOBs and Informix 7.X
---------------------------------------------------------------------
	
	This release now supports blob data types - byte and text. It also
	supports Informix 7.X stored procedure execution in the "sql run"
	command. 
	The syntax for running the stored procedures is identical to the
	one used in ISQL or DBACCESS programs provided by Informix.
	Text values are stored and retrieved as-is. Byte values are converted
	to hex on output and the input is assumed to be in hex.

	e.g.
	sql database db
	sql run "create table blob1 (x1 text, x2 char(10))"
	sql run "insert into blob1 values(?,?)" [exec cat /etc/passwd] "END"
	source sql.tcl 
	# contains the function sql_one
	sql_one "select * from blob1"
		# should return a list with two elements : contents of password 
		# file and the word END
	sql run "create table blob2 (x1 byte, x2 char(10))"
	sql run "insert into blob2 values(?,?)" 6d6d6d6d6d END
	sql_one "select * from blob2"
		# should return 6D6D6D6D6D and END in a list
	sql run "delete from blob1"
	sql run "insert into blob1 select * from blob2"
	sql_one "select * from blob1"
		# should return mmmmm and END in a list (since 6d is m in ascii)
	sql run "drop table blob1; drop table blob2"
	# sql_one "execute procedure ins_sel()" 

	A compatibility file called sql.tcl is also provided which allows
	programs which use sql_ calls to work with the sql command.

	Also using the sql_ calls will provide for easier migration to other
	database access routines.

	Two TCL functions in sql.tcl will allow for fetching one row
	from a cursor i.e. open cursor fetch one row and close cursor

	e.g.
	sql database db
	sql_one "select * from employee where emp_name = ?" "ABC"
		will fetch the first row 
	sql_onetrim "select * from employee"
		will fetch the first row and strip trailing blanks from the
		returned columns

	A windowing ISQL (plagiarized from Tom Pointdexter's Sybase 
	package) is provided. Run it by typing
	cd uco;wish -f wsql
	The wish should have ISQL and WISH-X extensions compiled in.

	You will be able to generally form SQL queries on the fly (without
	having to know SQL), look at different database tables etc. using
	this small but wonderful package. 

	This release compiles in the same manner as earlier releases
	(look at the compiling section in this document).

Informix SQL TCL - Release 3.1 - Minor fixes
---------------------------------------------------------------------

	Some minor fixes to code to workaround Informix bugs
	(Fixed sql_set_values to initialize sqlda pointer to NULL
	if sqlda's sqld element is 0; otherwise the pointer sqlvar is
	pointing to an illegal reference).
	Also added casts for calloc where appropriate.

	Removed wisql from the distribution since it did not work at all
	on TK4.1.