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Built-in aggregate functions (MIN, SUM, AVG, etc) should ignore NULL entires. (CVS 597)

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FossilOrigin-Name: 19ae12bef210ae5fe171f10833faa38d640c129f
This commit is contained in:
drh
2002-05-29 23:22:23 +00:00
parent f1756d2a79
commit 739105c72c
6 changed files with 46 additions and 43 deletions
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49
src/func.c
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@@ -16,7 +16,7 @@
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.17 2002/05/26 21:34:58 drh Exp $
** $Id: func.c,v 1.18 2002/05/29 23:22:23 drh Exp $
*/
#include <ctype.h>
#include <math.h>
@@ -254,6 +254,7 @@ static void nullifFunc(sqlite_func *context, int argc, const char **argv){
typedef struct SumCtx SumCtx;
struct SumCtx {
double sum; /* Sum of terms */
int cnt; /* Number of elements summed */
};
/*
@@ -261,12 +262,12 @@ struct SumCtx {
*/
static void sumStep(sqlite_func *context, int argc, const char **argv){
SumCtx *p;
double x;
if( argc<1 ) return;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p==0 ) return;
x = argv[0] ? atof(argv[0]) : 0.0;
p->sum += x;
if( p && argv[0] ){
p->sum += atof(argv[0]);
p->cnt++;
}
}
static void sumFinalize(sqlite_func *context){
SumCtx *p;
@@ -275,11 +276,9 @@ static void sumFinalize(sqlite_func *context){
}
static void avgFinalize(sqlite_func *context){
SumCtx *p;
double rN;
p = sqlite_aggregate_context(context, sizeof(*p));
rN = sqlite_aggregate_count(context);
if( p && rN>0.0 ){
sqlite_set_result_double(context, p->sum/rN);
if( p && p->cnt>0 ){
sqlite_set_result_double(context, p->sum/(double)p->cnt);
}
}
@@ -291,6 +290,7 @@ typedef struct StdDevCtx StdDevCtx;
struct StdDevCtx {
double sum; /* Sum of terms */
double sum2; /* Sum of the squares of terms */
int cnt; /* Number of terms counted */
};
#if 0 /* Omit because math library is required */
@@ -302,17 +302,20 @@ static void stdDevStep(sqlite_func *context, int argc, const char **argv){
double x;
if( argc<1 ) return;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p==0 ) return;
x = argv[0] ? atof(argv[0]) : 0.0;
p->sum += x;
p->sum2 += x*x;
if( p && argv[0] ){
x = atof(argv[0]);
p->sum += x;
p->sum2 += x*x;
p->cnt++;
}
}
static void stdDevFinalize(sqlite_func *context){
double rN = sqlite_aggregate_count(context);
StdDevCtx *p = sqlite_aggregate_context(context, sizeof(*p));
if( p && rN>1.0 ){
if( p && p->cnt>1 ){
double rCnt = cnt;
sqlite_set_result_double(context,
sqrt((p->sum2 - p->sum*p->sum/rN)/(rN-1.0)));
sqrt((p->sum2 - p->sum*p->sum/rCnt)/(rCnt-1.0)));
}
}
#endif
@@ -348,7 +351,6 @@ static void countFinalize(sqlite_func *context){
*/
typedef struct MinMaxCtx MinMaxCtx;
struct MinMaxCtx {
int isNull; /* True if the result should be NULL */
char *z; /* The best so far */
char zBuf[28]; /* Space that can be used for storage */
};
@@ -359,11 +361,7 @@ struct MinMaxCtx {
static void minStep(sqlite_func *context, int argc, const char **argv){
MinMaxCtx *p;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p==0 || argc<1 ) return;
if( argv[0]==0 || p->isNull ){
p->isNull = 1;
return;
}
if( p==0 || argc<1 || argv[0]==0 ) return;
if( sqlite_aggregate_count(context)==1 || sqliteCompare(argv[0],p->z)<0 ){
int len;
if( p->z && p->z!=p->zBuf ){
@@ -382,11 +380,7 @@ static void minStep(sqlite_func *context, int argc, const char **argv){
static void maxStep(sqlite_func *context, int argc, const char **argv){
MinMaxCtx *p;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p==0 || argc<1 ) return;
if( argv[0]==0 || p->isNull ){
p->isNull = 1;
return;
}
if( p==0 || argc<1 || argv[0]==0 ) return;
if( sqlite_aggregate_count(context)==1 || sqliteCompare(argv[0],p->z)>0 ){
int len;
if( p->z && p->z!=p->zBuf ){
@@ -405,7 +399,7 @@ static void maxStep(sqlite_func *context, int argc, const char **argv){
static void minMaxFinalize(sqlite_func *context){
MinMaxCtx *p;
p = sqlite_aggregate_context(context, sizeof(*p));
if( p && p->z && !p->isNull ){
if( p && p->z ){
sqlite_set_result_string(context, p->z, strlen(p->z));
}
if( p && p->z && p->z!=p->zBuf ){
@@ -438,6 +432,7 @@ void sqliteRegisterBuildinFunctions(sqlite *db){
{ "coalesce", -1, ifnullFunc },
{ "coalesce", 0, 0 },
{ "coalesce", 1, 0 },
{ "ifnull", 2, ifnullFunc },
{ "random", -1, randomFunc },
{ "like", 2, likeFunc },
{ "glob", 2, globFunc },