Index Page ekacec_c

A B C D E F G H I J K L M N O P Q R S T U V W X

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       void ekacec_c  ( SpiceInt          handle,
                        SpiceInt          segno,
                        SpiceInt          recno,
                        ConstSpiceChar  * column,
                        SpiceInt          nvals,
                        SpiceInt          vallen,
                        const void      * cvals,
                        SpiceBoolean      isnull )

#### Abstract

       Add data to a character column in a specified EK record.

#### Required_Reading

       EK

#### Keywords

       EK
       UTILITY

#### Brief_I/O

       Variable  I/O  Description
       --------  ---  --------------------------------------------------
       handle     I   EK file handle.
       segno      I   Index of segment containing record.
       recno      I   Record to which data is to be added.
       column     I   Column name.
       nvals      I   Number of values to add to column.
       vallen     I   Declared length of character values.
       cvals      I   Character values to add to column.
       isnull     I   Flag indicating whether column entry is null.

#### Detailed_Input

       handle         is the handle of an EK file open for write access.

       segno          is the number of the segment to which the record
                      is to be added.  EK segment numbers range from
                      0 to N-1, where N is the number of segments
                      in the kernel.

       recno          is the index of the record to which data is to be
                      added.  This record number is relative to the start
                      of the segment indicated by segno; the first
                      record in the segment has index 0.

       column         is the name of the column to which data is to be
                      added.

       nvals          is the number of entries in the value to be added to the
                      specified column.

       vallen         is the length of the strings in the cvals array, where
                      the length includes space for null terminators.

                      If the  column has fixed-size entries, then nvals
                      must equal the entry size for the specified column.

       cvals          is the set of values themselves.  The data values are
                      written into the specified column and record.

                      The array cvals should be declared with dimensions

                         [nelts][vallen]

                      where nelts is greater than or equal to nvals.

       isnull         is a logical flag indicating whether the entry is
                      null.  If isnull is SPICEFALSE, the column entry
                      defined by nvals and cvals is added to the
                      specified kernel file.

                      If isnull is SPICETRUE, nvals and cvals are ignored:
                      no data are written into the specified column entry.
                      The column entry is marked as a null value.

                      If the column has fixed-length, variable-size
                      entries, the number of entries is considered to
                      be 1.

#### Detailed_Output

       None.  See $Particulars for a description of the effect of this
       routine.

#### Parameters

       None.

#### Exceptions

       1)  If handle is invalid, the error will be diagnosed by routines
           called by this routine.

       2)  If segno is out of range, the error will be diagnosed by
           routines called by this routine.

       3)  If column is not the name of a declared column, the error
           will be diagnosed by routines called by this routine.

       4)  If column specifies a column of whose data type is not
           character, the error SPICE(WRONGDATATYPE) will be
           signaled.

       5)  If recno is out of range, the error will be diagnosed by
           routines called by this routine.

       6)  If the specified column has fixed-size entries and nvals
           does not match this size, the error will be diagnosed by
           routines called by this routine.

       7)  If the specified column has variable-size entries and nvals
           is non-positive, the error will be diagnosed by routines
           called by this routine.

       8)  If an attempt is made to add a null value to a column that
           doesn't take null values, the error will be diagnosed by
           routines called by this routine.

       9)  If column specifies a column of whose class is not
           a character class known to this routine, the error
           SPICE(NOCLASS) will be signaled.

       10) If an I/O error occurs while reading or writing the indicated
           file, the error will be diagnosed by routines called by this
           routine.

       11) If the input string pointer for column is null, the error
            SPICE(NULLPOINTER) will be signaled.

       12) If the input string column name has length zero, the error
           SPICE(EMPTYSTRING) will be signaled.

       13) If the string pointer for cvals is null, the error
           SPICE(NULLPOINTER) will be signaled.

       14) If the string length vallen is less than 2, the error
           SPICE(STRINGTOOSHORT) will be signaled.

#### Files

       See the EK Required Reading for a discussion of the EK file
       format.

#### Particulars

       This routine operates by side effects:  it modifies the named
       EK file by adding data to the specified record in the specified
       column.  Data may be added to a segment in random order; it is not
       necessary to fill in columns or rows sequentially.  Data may only
       be added one column entry at a time.

#### Examples

       1)  Add the value "999" to the third record of the column CCOL in
           the fifth segment of an EK file designated by HANDLE.

              #include "SpiceUsr.h"
                 .
                 .
                 .
              ekacec_c ( handle, 4, 2, "CCOL", 1, 4, "999", SPICEFALSE );

       2)  Same as (1), but this time add a null value.  The argument
           "999" is ignored because the null flag is set to SPICETRUE.

              #include "SpiceUsr.h"
                 .
                 .
                 .
              ekacec_c ( handle, 4, 2, "CCOL", 1, 4, "999", SPICETRUE );

       3)  Add an array cbuff of 10 values to the third record of the
           column CARRAY in the fifth segment of an EK file designated by
           handle.  We assume cbuff was declared as shown:

              SpiceChar cbuff[10][CBLEN];

              #include "SpiceUsr.h"
                 .
                 .
                 .
              ekacec_c ( handle,  4,      2,      "CARRAY",
                         10,      CBLEN,  cbuff,  SPICEFALSE );

       4)  A more detailed example:  append a record to a specified
           segment.

           Suppose we have an E-kernel named order_db.ek which contains
           records of orders for data products.  The E-kernel has a
           table called DATAORDERS that consists of the set of columns
           listed below:

              DATAORDERS

                 Column Name     Data Type
                 -----------     ---------
                 ORDER_ID        INTEGER
                 CUSTOMER_ID     INTEGER
                 LAST_NAME       CHARACTER*(*)
                 FIRST_NAME      CHARACTER*(*)
                 ORDER_DATE      TIME
                 COST            DOUBLE PRECISION

           The order database also has a table of items that have been
           ordered.  The columns of this table are shown below:

              DATAITEMS

                 Column Name     Data Type
                 -----------     ---------
                 ITEM_ID         INTEGER
                 ORDER_ID        INTEGER
                 ITEM_NAME       CHARACTER*(*)
                 DESCRIPTION     CHARACTER*(*)
                 PRICE           DOUBLE PRECISION

           We'll suppose that the file order_db.ek contains two segments,
           the first containing the DATAORDERS table and the second
           containing the DATAITEMS table.

           If we wanted to insert a new record into the DATAORDERS
           table in position 0, we'd make the following calls:

              #include "SpiceUsr.h"
                  .
                  .
                  .
              /.
              Open the database for write access.  This call is
              made when the file already exists.  See ekopn_c for
              an example of creating a new file.
              ./
              ekopw_c ( "order_db.ek", &handle );

              /.
              Append a new, empty record to the DATAORDERS
              table. Recall that the DATAORDERS table
              is in segment number 0.  The call will return
              the number of the new, empty record.
              ./
              ekappr_c ( handle, 0, &recno );

              /.
              At this point, the new record is empty.  A valid EK
              cannot contain empty records.  We fill in the data
              here.  Data items are filled in one column at a time.
              The order in which the columns are filled in is not
              important.  We use the ekace*_c (add column entry)
              routines to fill in column entries.  We'll assume
              that no entries are null.  All entries are scalar,
              so the entry size is 1.
              ./
              isnull  =  SPICEFALSE;
              size    =  1;

              /.
              The following variables will contain the data for
              the new record.
              ./
              ordid    =   10011;
              custid   =   531;
              lname    =   "scientist";
              fname    =   "joe";
              odate    =   "1995-sep-20";
              cost     =   5000.;

              /.
              Note that the names of the routines called
              correspond to the data types of the columns:  the
              last letter of the routine name is C, I, or D,
              depending on the data type.  Time values are
              converted to ET for storage.
              ./
              ekacei_c ( handle,  segno,  recno, "order_id",
                         size,    ordid,  isnull             );

              ekacei_c ( handle,  segno,  recno, "customer_id",
                         size,    custid, isnull              );

              ekacec_c ( handle,  segno,  recno, "last_name",
                         size,    vallen, lname,  isnull      );

              ekacec_c ( handle,  segno,  recno, "first_name",
                         size,    vallen, fname,  isnull      );

              utc2et_c ( odate,   &et );

              ekaced_c ( handle, segno,  recno, "order_date",
                         size,   et,     isnull               );

              ekaced_c ( handle, segno,  recno, "cost",
                         size,   cost,   isnull               );

              /.
              Close the file to make the update permanent.
              ./
              ekcls_c ( handle );

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman   (JPL)

#### Version

       -CSPICE Version 1.0.0, 28-AUG-2001 (NJB)

#### Index_Entries

       add character data to EK column
       add data to EK
       write character data to EK column

#### Link to routine ekacec_c source file ekacec_c.c

    Wed Apr  5 17:54:33 2017