36.15. Informix Compatibility Mode

36.15. Informix Compatibility Mode
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36.15.1. Additional Types
36.15.2. Additional/Missing Embedded SQL Statements
36.15.3. Informix-compatible SQLDA Descriptor Areas
36.15.4. Additional Functions
36.15.5. Additional Constants

+ ecpg can be run in a so-called Informix compatibility mode. If + this mode is active, it tries to behave as if it were the Informix + precompiler for Informix E/SQL. Generally spoken this will allow you to use + the dollar sign instead of the EXEC SQL primitive to introduce + embedded SQL commands: +

+$int j = 3;
+$CONNECT TO :dbname;
+$CREATE TABLE test(i INT PRIMARY KEY, j INT);
+$INSERT INTO test(i, j) VALUES (7, :j);
+$COMMIT;
+

Note

+ There must not be any white space between the $ + and a following preprocessor directive, that is, + include, define, ifdef, + etc. Otherwise, the preprocessor will parse the token as a host + variable. +

+ There are two compatibility modes: INFORMIX, INFORMIX_SE +

+ When linking programs that use this compatibility mode, remember to link + against libcompat that is shipped with ECPG. +

+ Besides the previously explained syntactic sugar, the Informix compatibility + mode ports some functions for input, output and transformation of data as + well as embedded SQL statements known from E/SQL to ECPG. +

+ Informix compatibility mode is closely connected to the pgtypeslib library + of ECPG. pgtypeslib maps SQL data types to data types within the C host + program and most of the additional functions of the Informix compatibility + mode allow you to operate on those C host program types. Note however that + the extent of the compatibility is limited. It does not try to copy Informix + behavior; it allows you to do more or less the same operations and gives + you functions that have the same name and the same basic behavior but it is + no drop-in replacement if you are using Informix at the moment. Moreover, + some of the data types are different. For example, + PostgreSQL's datetime and interval types do not + know about ranges like for example YEAR TO MINUTE so you won't + find support in ECPG for that either. +

36.15.1. Additional Types

+ The Informix-special "string" pseudo-type for storing right-trimmed character string data is now + supported in Informix-mode without using typedef. In fact, in Informix-mode, + ECPG refuses to process source files that contain typedef sometype string; +

+EXEC SQL BEGIN DECLARE SECTION;
+string userid; /* this variable will contain trimmed data */
+EXEC SQL END DECLARE SECTION;
+
+EXEC SQL FETCH MYCUR INTO :userid;
+

36.15.2. Additional/Missing Embedded SQL Statements

CLOSE DATABASE

+ This statement closes the current connection. In fact, this is a + synonym for ECPG's DISCONNECT CURRENT: +

+$CLOSE DATABASE;                /* close the current connection */
+EXEC SQL CLOSE DATABASE;
+

FREE cursor_name

+ Due to differences in how ECPG works compared to Informix's ESQL/C (namely, which steps + are purely grammar transformations and which steps rely on the underlying run-time library) + there is no FREE cursor_name statement in ECPG. This is because in ECPG, + DECLARE CURSOR doesn't translate to a function call into + the run-time library that uses to the cursor name. This means that there's no run-time + bookkeeping of SQL cursors in the ECPG run-time library, only in the PostgreSQL server. +

FREE statement_name

+ FREE statement_name is a synonym for DEALLOCATE PREPARE statement_name. +

36.15.3. Informix-compatible SQLDA Descriptor Areas

+ Informix-compatible mode supports a different structure than the one described in + Section 36.7.2. See below: +

+struct sqlvar_compat
+{
+    short   sqltype;
+    int     sqllen;
+    char   *sqldata;
+    short  *sqlind;
+    char   *sqlname;
+    char   *sqlformat;
+    short   sqlitype;
+    short   sqlilen;
+    char   *sqlidata;
+    int     sqlxid;
+    char   *sqltypename;
+    short   sqltypelen;
+    short   sqlownerlen;
+    short   sqlsourcetype;
+    char   *sqlownername;
+    int     sqlsourceid;
+    char   *sqlilongdata;
+    int     sqlflags;
+    void   *sqlreserved;
+};
+
+struct sqlda_compat
+{
+    short  sqld;
+    struct sqlvar_compat *sqlvar;
+    char   desc_name[19];
+    short  desc_occ;
+    struct sqlda_compat *desc_next;
+    void  *reserved;
+};
+
+typedef struct sqlvar_compat    sqlvar_t;
+typedef struct sqlda_compat     sqlda_t;
+

+ The global properties are: +

sqld: + The number of fields in the SQLDA descriptor. +
sqlvar: + Pointer to the per-field properties. +
desc_name: + Unused, filled with zero-bytes. +
desc_occ: + Size of the allocated structure. +
desc_next: + Pointer to the next SQLDA structure if the result set contains more than one record. +
reserved: + Unused pointer, contains NULL. Kept for Informix-compatibility. +

+ + The per-field properties are below, they are stored in the sqlvar array: + +

sqltype

+ Type of the field. Constants are in sqltypes.h +

sqllen

+ Length of the field data. +

sqldata

+ Pointer to the field data. The pointer is of char * type, + the data pointed by it is in a binary format. Example: +

+int intval;
+
+switch (sqldata->sqlvar[i].sqltype)
+{
+    case SQLINTEGER:
+        intval = *(int *)sqldata->sqlvar[i].sqldata;
+        break;
+  ...
+}
+

sqlind

+ Pointer to the NULL indicator. If returned by DESCRIBE or FETCH then it's always a valid pointer. + If used as input for EXECUTE ... USING sqlda; then NULL-pointer value means + that the value for this field is non-NULL. Otherwise a valid pointer and sqlitype + has to be properly set. Example: +

+if (*(int2 *)sqldata->sqlvar[i].sqlind != 0)
+    printf("value is NULL\n");
+

sqlname

+ Name of the field. 0-terminated string. +

sqlformat

+ Reserved in Informix, value of PQfformat for the field. +

sqlitype

+ Type of the NULL indicator data. It's always SQLSMINT when returning data from the server. + When the SQLDA is used for a parameterized query, the data is treated + according to the set type. +

sqlilen

+ Length of the NULL indicator data. +

sqlxid

+ Extended type of the field, result of PQftype. +

sqltypename sqltypelen sqlownerlen sqlsourcetype sqlownername sqlsourceid sqlflags sqlreserved

+ Unused. +

sqlilongdata

+ It equals to sqldata if sqllen is larger than 32kB. +

+ + Example: +

+EXEC SQL INCLUDE sqlda.h;
+
+    sqlda_t        *sqlda; /* This doesn't need to be under embedded DECLARE SECTION */
+
+    EXEC SQL BEGIN DECLARE SECTION;
+    char *prep_stmt = "select * from table1";
+    int i;
+    EXEC SQL END DECLARE SECTION;
+
+    ...
+
+    EXEC SQL PREPARE mystmt FROM :prep_stmt;
+
+    EXEC SQL DESCRIBE mystmt INTO sqlda;
+
+    printf("# of fields: %d\n", sqlda->sqld);
+    for (i = 0; i < sqlda->sqld; i++)
+      printf("field %d: \"%s\"\n", sqlda->sqlvar[i]->sqlname);
+
+    EXEC SQL DECLARE mycursor CURSOR FOR mystmt;
+    EXEC SQL OPEN mycursor;
+    EXEC SQL WHENEVER NOT FOUND GOTO out;
+
+    while (1)
+    {
+      EXEC SQL FETCH mycursor USING sqlda;
+    }
+
+    EXEC SQL CLOSE mycursor;
+
+    free(sqlda); /* The main structure is all to be free(),
+                  * sqlda and sqlda->sqlvar is in one allocated area */
+

+ For more information, see the sqlda.h header and the + src/interfaces/ecpg/test/compat_informix/sqlda.pgc regression test. +

36.15.4. Additional Functions

decadd

+ Add two decimal type values. +

+int decadd(decimal *arg1, decimal *arg2, decimal *sum);
+

+ The function receives a pointer to the first operand of type decimal + (arg1), a pointer to the second operand of type decimal + (arg2) and a pointer to a value of type decimal that will + contain the sum (sum). On success, the function returns 0. + ECPG_INFORMIX_NUM_OVERFLOW is returned in case of overflow and + ECPG_INFORMIX_NUM_UNDERFLOW in case of underflow. -1 is returned for + other failures and errno is set to the respective errno number of the + pgtypeslib. +

deccmp

+ Compare two variables of type decimal. +

+int deccmp(decimal *arg1, decimal *arg2);
+

+ The function receives a pointer to the first decimal value + (arg1), a pointer to the second decimal value + (arg2) and returns an integer value that indicates which is + the bigger value. +

+ 1, if the value that arg1 points to is bigger than the + value that var2 points to +
+ -1, if the value that arg1 points to is smaller than the + value that arg2 points to
+ 0, if the value that arg1 points to and the value that + arg2 points to are equal +

deccopy

+ Copy a decimal value. +

+void deccopy(decimal *src, decimal *target);
+

+ The function receives a pointer to the decimal value that should be + copied as the first argument (src) and a pointer to the + target structure of type decimal (target) as the second + argument. +

deccvasc

+ Convert a value from its ASCII representation into a decimal type. +

+int deccvasc(char *cp, int len, decimal *np);
+

+ The function receives a pointer to string that contains the string + representation of the number to be converted (cp) as well + as its length len. np is a pointer to the + decimal value that saves the result of the operation. +

+ Valid formats are for example: + -2, + .794, + +3.44, + 592.49E07 or + -32.84e-4. +

+ The function returns 0 on success. If overflow or underflow occurred, + ECPG_INFORMIX_NUM_OVERFLOW or + ECPG_INFORMIX_NUM_UNDERFLOW is returned. If the ASCII + representation could not be parsed, + ECPG_INFORMIX_BAD_NUMERIC is returned or + ECPG_INFORMIX_BAD_EXPONENT if this problem occurred while + parsing the exponent. +

deccvdbl

+ Convert a value of type double to a value of type decimal. +

+int deccvdbl(double dbl, decimal *np);
+

+ The function receives the variable of type double that should be + converted as its first argument (dbl). As the second + argument (np), the function receives a pointer to the + decimal variable that should hold the result of the operation. +

+ The function returns 0 on success and a negative value if the + conversion failed. +

deccvint

+ Convert a value of type int to a value of type decimal. +

+int deccvint(int in, decimal *np);
+

+ The function receives the variable of type int that should be + converted as its first argument (in). As the second + argument (np), the function receives a pointer to the + decimal variable that should hold the result of the operation. +

+ The function returns 0 on success and a negative value if the + conversion failed. +

deccvlong

+ Convert a value of type long to a value of type decimal. +

+int deccvlong(long lng, decimal *np);
+

+ The function receives the variable of type long that should be + converted as its first argument (lng). As the second + argument (np), the function receives a pointer to the + decimal variable that should hold the result of the operation. +

+ The function returns 0 on success and a negative value if the + conversion failed. +

decdiv

+ Divide two variables of type decimal. +

+int decdiv(decimal *n1, decimal *n2, decimal *result);
+

+ The function receives pointers to the variables that are the first + (n1) and the second (n2) operands and + calculates n1/n2. result is a + pointer to the variable that should hold the result of the operation. +

+ On success, 0 is returned and a negative value if the division fails. + If overflow or underflow occurred, the function returns + ECPG_INFORMIX_NUM_OVERFLOW or + ECPG_INFORMIX_NUM_UNDERFLOW respectively. If an attempt to + divide by zero is observed, the function returns + ECPG_INFORMIX_DIVIDE_ZERO. +

decmul

+ Multiply two decimal values. +

+int decmul(decimal *n1, decimal *n2, decimal *result);
+

+ The function receives pointers to the variables that are the first + (n1) and the second (n2) operands and + calculates n1*n2. result is a + pointer to the variable that should hold the result of the operation. +

+ On success, 0 is returned and a negative value if the multiplication + fails. If overflow or underflow occurred, the function returns + ECPG_INFORMIX_NUM_OVERFLOW or + ECPG_INFORMIX_NUM_UNDERFLOW respectively. +

decsub

+ Subtract one decimal value from another. +

+int decsub(decimal *n1, decimal *n2, decimal *result);
+

+ The function receives pointers to the variables that are the first + (n1) and the second (n2) operands and + calculates n1-n2. result is a + pointer to the variable that should hold the result of the operation. +

+ On success, 0 is returned and a negative value if the subtraction + fails. If overflow or underflow occurred, the function returns + ECPG_INFORMIX_NUM_OVERFLOW or + ECPG_INFORMIX_NUM_UNDERFLOW respectively. +

dectoasc

+ Convert a variable of type decimal to its ASCII representation in a C + char* string. +

+int dectoasc(decimal *np, char *cp, int len, int right)
+

+ The function receives a pointer to a variable of type decimal + (np) that it converts to its textual representation. + cp is the buffer that should hold the result of the + operation. The parameter right specifies, how many digits + right of the decimal point should be included in the output. The result + will be rounded to this number of decimal digits. Setting + right to -1 indicates that all available decimal digits + should be included in the output. If the length of the output buffer, + which is indicated by len is not sufficient to hold the + textual representation including the trailing zero byte, only a + single * character is stored in the result and -1 is + returned. +

+ The function returns either -1 if the buffer cp was too + small or ECPG_INFORMIX_OUT_OF_MEMORY if memory was + exhausted. +

dectodbl

+ Convert a variable of type decimal to a double. +

+int dectodbl(decimal *np, double *dblp);
+

+ The function receives a pointer to the decimal value to convert + (np) and a pointer to the double variable that + should hold the result of the operation (dblp). +

+ On success, 0 is returned and a negative value if the conversion + failed. +

dectoint

+ Convert a variable to type decimal to an integer. +

+int dectoint(decimal *np, int *ip);
+

+ The function receives a pointer to the decimal value to convert + (np) and a pointer to the integer variable that + should hold the result of the operation (ip). +

+ On success, 0 is returned and a negative value if the conversion + failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW + is returned. +

+ Note that the ECPG implementation differs from the Informix + implementation. Informix limits an integer to the range from -32767 to + 32767, while the limits in the ECPG implementation depend on the + architecture (INT_MIN .. INT_MAX). +

dectolong

+ Convert a variable to type decimal to a long integer. +

+int dectolong(decimal *np, long *lngp);
+

+ The function receives a pointer to the decimal value to convert + (np) and a pointer to the long variable that + should hold the result of the operation (lngp). +

+ On success, 0 is returned and a negative value if the conversion + failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW + is returned. +

+ Note that the ECPG implementation differs from the Informix + implementation. Informix limits a long integer to the range from + -2,147,483,647 to 2,147,483,647, while the limits in the ECPG + implementation depend on the architecture (-LONG_MAX .. + LONG_MAX). +

rdatestr

+ Converts a date to a C char* string. +

+int rdatestr(date d, char *str);
+

+ The function receives two arguments, the first one is the date to + convert (d) and the second one is a pointer to the target + string. The output format is always yyyy-mm-dd, so you need + to allocate at least 11 bytes (including the zero-byte terminator) for the + string. +

+ The function returns 0 on success and a negative value in case of + error. +

+ Note that ECPG's implementation differs from the Informix + implementation. In Informix the format can be influenced by setting + environment variables. In ECPG however, you cannot change the output + format. +

rstrdate

+ Parse the textual representation of a date. +

+int rstrdate(char *str, date *d);
+

+ The function receives the textual representation of the date to convert + (str) and a pointer to a variable of type date + (d). This function does not allow you to specify a format + mask. It uses the default format mask of Informix which is + mm/dd/yyyy. Internally, this function is implemented by + means of rdefmtdate. Therefore, rstrdate is + not faster and if you have the choice you should opt for + rdefmtdate which allows you to specify the format mask + explicitly. +

+ The function returns the same values as rdefmtdate. +

rtoday

+ Get the current date. +

+void rtoday(date *d);
+

+ The function receives a pointer to a date variable (d) + that it sets to the current date. +

+ Internally this function uses the PGTYPESdate_today + function. +

rjulmdy

+ Extract the values for the day, the month and the year from a variable + of type date. +

+int rjulmdy(date d, short mdy[3]);
+

+ The function receives the date d and a pointer to an array + of 3 short integer values mdy. The variable name indicates + the sequential order: mdy[0] will be set to contain the + number of the month, mdy[1] will be set to the value of the + day and mdy[2] will contain the year. +

+ The function always returns 0 at the moment. +

+ Internally the function uses the PGTYPESdate_julmdy + function. +

rdefmtdate

+ Use a format mask to convert a character string to a value of type + date. +

+int rdefmtdate(date *d, char *fmt, char *str);
+

+ The function receives a pointer to the date value that should hold the + result of the operation (d), the format mask to use for + parsing the date (fmt) and the C char* string containing + the textual representation of the date (str). The textual + representation is expected to match the format mask. However you do not + need to have a 1:1 mapping of the string to the format mask. The + function only analyzes the sequential order and looks for the literals + yy or yyyy that indicate the + position of the year, mm to indicate the position of + the month and dd to indicate the position of the + day. +

+ The function returns the following values: +

+ 0 - The function terminated successfully. +
+ ECPG_INFORMIX_ENOSHORTDATE - The date does not contain + delimiters between day, month and year. In this case the input + string must be exactly 6 or 8 bytes long but isn't. +
+ ECPG_INFORMIX_ENOTDMY - The format string did not + correctly indicate the sequential order of year, month and day. +
+ ECPG_INFORMIX_BAD_DAY - The input string does not + contain a valid day. +
+ ECPG_INFORMIX_BAD_MONTH - The input string does not + contain a valid month. +
+ ECPG_INFORMIX_BAD_YEAR - The input string does not + contain a valid year. +

+ Internally this function is implemented to use the PGTYPESdate_defmt_asc function. See the reference there for a + table of example input. +

rfmtdate

+ Convert a variable of type date to its textual representation using a + format mask. +

+int rfmtdate(date d, char *fmt, char *str);
+

+ The function receives the date to convert (d), the format + mask (fmt) and the string that will hold the textual + representation of the date (str). +

+ On success, 0 is returned and a negative value if an error occurred. +

+ Internally this function uses the PGTYPESdate_fmt_asc + function, see the reference there for examples. +

rmdyjul

+ Create a date value from an array of 3 short integers that specify the + day, the month and the year of the date. +

+int rmdyjul(short mdy[3], date *d);
+

+ The function receives the array of the 3 short integers + (mdy) and a pointer to a variable of type date that should + hold the result of the operation. +

+ Currently the function returns always 0. +

+ Internally the function is implemented to use the function PGTYPESdate_mdyjul. +

rdayofweek

+ Return a number representing the day of the week for a date value. +

+int rdayofweek(date d);
+

+ The function receives the date variable d as its only + argument and returns an integer that indicates the day of the week for + this date. +

+ 0 - Sunday +
+ 1 - Monday +
+ 2 - Tuesday +
+ 3 - Wednesday +
+ 4 - Thursday +
+ 5 - Friday +
+ 6 - Saturday +

+ Internally the function is implemented to use the function PGTYPESdate_dayofweek. +

dtcurrent

+ Retrieve the current timestamp. +

+void dtcurrent(timestamp *ts);
+

+ The function retrieves the current timestamp and saves it into the + timestamp variable that ts points to. +

dtcvasc

+ Parses a timestamp from its textual representation + into a timestamp variable. +

+int dtcvasc(char *str, timestamp *ts);
+

+ The function receives the string to parse (str) and a + pointer to the timestamp variable that should hold the result of the + operation (ts). +

+ The function returns 0 on success and a negative value in case of + error. +

+ Internally this function uses the PGTYPEStimestamp_from_asc function. See the reference there + for a table with example inputs. +

dtcvfmtasc

+ Parses a timestamp from its textual representation + using a format mask into a timestamp variable. +

+dtcvfmtasc(char *inbuf, char *fmtstr, timestamp *dtvalue)
+

+ The function receives the string to parse (inbuf), the + format mask to use (fmtstr) and a pointer to the timestamp + variable that should hold the result of the operation + (dtvalue). +

+ This function is implemented by means of the PGTYPEStimestamp_defmt_asc function. See the documentation + there for a list of format specifiers that can be used. +

+ The function returns 0 on success and a negative value in case of + error. +

dtsub

+ Subtract one timestamp from another and return a variable of type + interval. +

+int dtsub(timestamp *ts1, timestamp *ts2, interval *iv);
+

+ The function will subtract the timestamp variable that ts2 + points to from the timestamp variable that ts1 points to + and will store the result in the interval variable that iv + points to. +

+ Upon success, the function returns 0 and a negative value if an + error occurred. +

dttoasc

+ Convert a timestamp variable to a C char* string. +

+int dttoasc(timestamp *ts, char *output);
+

+ The function receives a pointer to the timestamp variable to convert + (ts) and the string that should hold the result of the + operation (output). It converts ts to its + textual representation according to the SQL standard, which is + be YYYY-MM-DD HH:MM:SS. +

+ Upon success, the function returns 0 and a negative value if an + error occurred. +

dttofmtasc

+ Convert a timestamp variable to a C char* using a format mask. +

+int dttofmtasc(timestamp *ts, char *output, int str_len, char *fmtstr);
+

+ The function receives a pointer to the timestamp to convert as its + first argument (ts), a pointer to the output buffer + (output), the maximal length that has been allocated for + the output buffer (str_len) and the format mask to + use for the conversion (fmtstr). +

+ Upon success, the function returns 0 and a negative value if an + error occurred. +

+ Internally, this function uses the PGTYPEStimestamp_fmt_asc function. See the reference there for + information on what format mask specifiers can be used. +

intoasc

+ Convert an interval variable to a C char* string. +

+int intoasc(interval *i, char *str);
+

+ The function receives a pointer to the interval variable to convert + (i) and the string that should hold the result of the + operation (str). It converts i to its + textual representation according to the SQL standard, which is + be YYYY-MM-DD HH:MM:SS. +

+ Upon success, the function returns 0 and a negative value if an + error occurred. +

rfmtlong

+ Convert a long integer value to its textual representation using a + format mask. +

+int rfmtlong(long lng_val, char *fmt, char *outbuf);
+

+ The function receives the long value lng_val, the format + mask fmt and a pointer to the output buffer + outbuf. It converts the long value according to the format + mask to its textual representation. +

+ The format mask can be composed of the following format specifying + characters: +

+ * (asterisk) - if this position would be blank + otherwise, fill it with an asterisk. +
+ & (ampersand) - if this position would be + blank otherwise, fill it with a zero. +
+ # - turn leading zeroes into blanks. +
+ < - left-justify the number in the string. +
+ , (comma) - group numbers of four or more digits + into groups of three digits separated by a comma. +
+ . (period) - this character separates the + whole-number part of the number from the fractional part. +
+ - (minus) - the minus sign appears if the number + is a negative value. +
+ + (plus) - the plus sign appears if the number is + a positive value. +
+ ( - this replaces the minus sign in front of the + negative number. The minus sign will not appear. +
+ ) - this character replaces the minus and is + printed behind the negative value. +
+ $ - the currency symbol. +

rupshift

+ Convert a string to upper case. +

+void rupshift(char *str);
+

+ The function receives a pointer to the string and transforms every + lower case character to upper case. +

byleng

+ Return the number of characters in a string without counting trailing + blanks. +

+int byleng(char *str, int len);
+

+ The function expects a fixed-length string as its first argument + (str) and its length as its second argument + (len). It returns the number of significant characters, + that is the length of the string without trailing blanks. +

ldchar

+ Copy a fixed-length string into a null-terminated string. +

+void ldchar(char *src, int len, char *dest);
+

+ The function receives the fixed-length string to copy + (src), its length (len) and a pointer to the + destination memory (dest). Note that you need to reserve at + least len+1 bytes for the string that dest + points to. The function copies at most len bytes to the new + location (less if the source string has trailing blanks) and adds the + null-terminator. +

rgetmsg

+int rgetmsg(int msgnum, char *s, int maxsize);
+

+ This function exists but is not implemented at the moment! +

rtypalign

+int rtypalign(int offset, int type);
+

+ This function exists but is not implemented at the moment! +

rtypmsize

+int rtypmsize(int type, int len);
+

+ This function exists but is not implemented at the moment! +

rtypwidth

+int rtypwidth(int sqltype, int sqllen);
+

+ This function exists but is not implemented at the moment! +

rsetnull

+ Set a variable to NULL. +

+int rsetnull(int t, char *ptr);
+

+ The function receives an integer that indicates the type of the + variable and a pointer to the variable itself that is cast to a C + char* pointer. +

+ The following types exist: +

+ CCHARTYPE - For a variable of type char or char* +
+ CSHORTTYPE - For a variable of type short int +
+ CINTTYPE - For a variable of type int +
+ CBOOLTYPE - For a variable of type boolean +
+ CFLOATTYPE - For a variable of type float +
+ CLONGTYPE - For a variable of type long +
+ CDOUBLETYPE - For a variable of type double +
+ CDECIMALTYPE - For a variable of type decimal +
+ CDATETYPE - For a variable of type date +
+ CDTIMETYPE - For a variable of type timestamp +

+ Here is an example of a call to this function: +

+$char c[] = "abc       ";
+$short s = 17;
+$int i = -74874;
+
+rsetnull(CCHARTYPE, (char *) c);
+rsetnull(CSHORTTYPE, (char *) &s);
+rsetnull(CINTTYPE, (char *) &i);
+
+

risnull

+ Test if a variable is NULL. +

+int risnull(int t, char *ptr);
+

+ The function receives the type of the variable to test (t) + as well a pointer to this variable (ptr). Note that the + latter needs to be cast to a char*. See the function rsetnull for a list of possible variable types. +

+ Here is an example of how to use this function: +

+$char c[] = "abc       ";
+$short s = 17;
+$int i = -74874;
+
+risnull(CCHARTYPE, (char *) c);
+risnull(CSHORTTYPE, (char *) &s);
+risnull(CINTTYPE, (char *) &i);
+
+

36.15.5. Additional Constants

+ Note that all constants here describe errors and all of them are defined + to represent negative values. In the descriptions of the different + constants you can also find the value that the constants represent in the + current implementation. However you should not rely on this number. You can + however rely on the fact all of them are defined to represent negative + values. +

ECPG_INFORMIX_NUM_OVERFLOW: + Functions return this value if an overflow occurred in a + calculation. Internally it is defined as -1200 (the Informix + definition). +
ECPG_INFORMIX_NUM_UNDERFLOW: + Functions return this value if an underflow occurred in a calculation. + Internally it is defined as -1201 (the Informix definition). +
ECPG_INFORMIX_DIVIDE_ZERO: + Functions return this value if an attempt to divide by zero is + observed. Internally it is defined as -1202 (the Informix definition). +
ECPG_INFORMIX_BAD_YEAR: + Functions return this value if a bad value for a year was found while + parsing a date. Internally it is defined as -1204 (the Informix + definition). +
ECPG_INFORMIX_BAD_MONTH: + Functions return this value if a bad value for a month was found while + parsing a date. Internally it is defined as -1205 (the Informix + definition). +
ECPG_INFORMIX_BAD_DAY: + Functions return this value if a bad value for a day was found while + parsing a date. Internally it is defined as -1206 (the Informix + definition). +
ECPG_INFORMIX_ENOSHORTDATE: + Functions return this value if a parsing routine needs a short date + representation but did not get the date string in the right length. + Internally it is defined as -1209 (the Informix definition). +
ECPG_INFORMIX_DATE_CONVERT: + Functions return this value if an error occurred during date + formatting. Internally it is defined as -1210 (the + Informix definition). +
ECPG_INFORMIX_OUT_OF_MEMORY: + Functions return this value if memory was exhausted during + their operation. Internally it is defined as -1211 (the + Informix definition). +
ECPG_INFORMIX_ENOTDMY: + Functions return this value if a parsing routine was supposed to get a + format mask (like mmddyy) but not all fields were listed + correctly. Internally it is defined as -1212 (the Informix definition). +
ECPG_INFORMIX_BAD_NUMERIC: + Functions return this value either if a parsing routine cannot parse + the textual representation for a numeric value because it contains + errors or if a routine cannot complete a calculation involving numeric + variables because at least one of the numeric variables is invalid. + Internally it is defined as -1213 (the Informix definition). +
ECPG_INFORMIX_BAD_EXPONENT: + Functions return this value if a parsing routine cannot parse + an exponent. Internally it is defined as -1216 (the + Informix definition). +
ECPG_INFORMIX_BAD_DATE: + Functions return this value if a parsing routine cannot parse + a date. Internally it is defined as -1218 (the + Informix definition). +
ECPG_INFORMIX_EXTRA_CHARS: + Functions return this value if a parsing routine is passed extra + characters it cannot parse. Internally it is defined as -1264 (the + Informix definition). +