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Improve the layer extent calculation of the MSSQL driver (#5781)
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@szekerest
szekerest committed Apr 12, 2019
1 parent 848b243 commit 866773b
Showing 1 changed file with 160 additions and 26 deletions.
186 changes: 160 additions & 26 deletions mapmssql2008.c
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Expand Up @@ -247,6 +247,7 @@ typedef struct ms_MSSQL2008_layer_info_t {
char *user_srid; /* zero length = calculate, non-zero means using this value! */
char *index_name; /* hopefully this isn't necessary - but if the optimizer ain't cuttin' it... */
char *sort_spec; /* the sort by specification which should be applied to the generated select statement */
int mssqlversion_major; /* the sql server major version number */
SQLSMALLINT *itemtypes; /* storing the sql field types for further reference */

msODBCconn * conn; /* Connection to db */
Expand Down Expand Up @@ -973,6 +974,7 @@ int msMSSQL2008LayerOpen(layerObj *layer)
layerinfo->sort_spec = NULL;
layerinfo->conn = NULL;
layerinfo->itemtypes = NULL;
layerinfo->mssqlversion_major = 0;

layerinfo->conn = (msODBCconn *) msConnPoolRequest(layer);

Expand Down Expand Up @@ -1102,26 +1104,162 @@ int msMSSQL2008LayerInitItemInfo(layerObj *layer)
return MS_SUCCESS;
}

static int getMSSQLMajorVersion(layerObj* layer)
{
msMSSQL2008LayerInfo *layerinfo = getMSSQL2008LayerInfo(layer);
if (layerinfo == NULL)
return 0;

if (layerinfo->mssqlversion_major == 0) {
char* mssqlversion_major = msLayerGetProcessingKey(layer, "MSSQL_VERSION_MAJOR");
if (mssqlversion_major != NULL) {
layerinfo->mssqlversion_major = atoi(mssqlversion_major);
}
else {
/* need to query from database */
if (executeSQL(layerinfo->conn, "SELECT SERVERPROPERTY('ProductVersion')")) {
SQLRETURN rc = SQLFetch(layerinfo->conn->hstmt);
if (rc == SQL_SUCCESS || rc == SQL_SUCCESS_WITH_INFO) {
/* process results */
char result_data[256];
SQLLEN retLen = 0;

rc = SQLGetData(layerinfo->conn->hstmt, 1, SQL_C_CHAR, result_data, sizeof(result_data), &retLen);

if (rc != SQL_ERROR) {
result_data[retLen] = 0;
layerinfo->mssqlversion_major = atoi(result_data);
}
}
}
}
}

return layerinfo->mssqlversion_major;
}

/* Get the layer extent as specified in the mapfile or a largest area */
/* covering all features */
int msMSSQL2008LayerGetExtent(layerObj *layer, rectObj *extent)
{
if(layer->debug) {
msDebug("msMSSQL2008LayerGetExtent called\n");
}
msMSSQL2008LayerInfo *layerinfo;
char *query = 0;
char result_data[256];
SQLLEN retLen;
SQLRETURN rc;

if(layer->debug) {
msDebug("msMSSQL2008LayerGetExtent called\n");
}

if (layer->extent.minx == -1.0 && layer->extent.miny == -1.0 &&
layer->extent.maxx == -1.0 && layer->extent.maxy == -1.0) {
extent->minx = extent->miny = -1.0 * FLT_MAX;
extent->maxx = extent->maxy = FLT_MAX;
} else {
extent->minx = layer->extent.minx;
extent->miny = layer->extent.miny;
extent->maxx = layer->extent.maxx;
extent->maxy = layer->extent.maxy;
}
if (!(layer->extent.minx == -1.0 && layer->extent.miny == -1.0 &&
layer->extent.maxx == -1.0 && layer->extent.maxy == -1.0)) {
/* extent was already set */
extent->minx = layer->extent.minx;
extent->miny = layer->extent.miny;
extent->maxx = layer->extent.maxx;
extent->maxy = layer->extent.maxy;
}

return MS_SUCCESS;
layerinfo = getMSSQL2008LayerInfo(layer);

if (!layerinfo) {
msSetError(MS_QUERYERR, "GetExtent called with layerinfo = NULL", "msMSSQL2008LayerGetExtent()");
return MS_FAILURE;
}

/* set up statement */
if (getMSSQLMajorVersion(layer) >= 11) {
if (strcasecmp(layerinfo->geom_column_type, "geography") == 0) {
query = msStringConcatenate(query, "WITH extent(extentcol) AS (SELECT geometry::EnvelopeAggregate(geometry::STGeomFromWKB(");
query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".STAsBinary(), ");
query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".STSrid)");
}
else {
query = msStringConcatenate(query, "WITH extent(extentcol) AS (SELECT geometry::EnvelopeAggregate(");
query = msStringConcatenate(query, layerinfo->geom_column);
}
query = msStringConcatenate(query, ".MakeValid()) AS extentcol FROM ");
query = msStringConcatenate(query, layerinfo->geom_table);
query = msStringConcatenate(query, ") SELECT extentcol.STPointN(1).STX, extentcol.STPointN(1).STY, extentcol.STPointN(3).STX, extentcol.STPointN(3).STY FROM extent");
}
else {
if (strcasecmp(layerinfo->geom_column_type, "geography") == 0) {
query = msStringConcatenate(query, "WITH ENVELOPE as (SELECT geometry::STGeomFromWKB(");
query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".STAsBinary(), ");
query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".STSrid)");
}
else {
query = msStringConcatenate(query, "WITH ENVELOPE as (SELECT ");
query = msStringConcatenate(query, layerinfo->geom_column);
}
query = msStringConcatenate(query, ".MakeValid().STEnvelope() as envelope from ");
query = msStringConcatenate(query, layerinfo->geom_table);
query = msStringConcatenate(query, "), CORNERS as (SELECT envelope.STPointN(1) as point from ENVELOPE UNION ALL select envelope.STPointN(3) from ENVELOPE) SELECT MIN(point.STX), MIN(point.STY), MAX(point.STX), MAX(point.STY) FROM CORNERS");
}

if (!executeSQL(layerinfo->conn, query)) {
msFree(query);
return MS_FAILURE;
}

msFree(query);

/* process results */
rc = SQLFetch(layerinfo->conn->hstmt);

if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) {
if (layer->debug) {
msDebug("msMSSQL2008LayerGetExtent: No results found.\n");
}
return MS_FAILURE;
}

rc = SQLGetData(layerinfo->conn->hstmt, 1, SQL_C_CHAR, result_data, sizeof(result_data), &retLen);
if (rc == SQL_ERROR) {
msSetError(MS_QUERYERR, "Failed to get MinX value", "msMSSQL2008LayerGetExtent()");
return MS_FAILURE;
}

result_data[retLen] = 0;

extent->minx = atof(result_data);

rc = SQLGetData(layerinfo->conn->hstmt, 2, SQL_C_CHAR, result_data, sizeof(result_data), &retLen);
if (rc == SQL_ERROR) {
msSetError(MS_QUERYERR, "Failed to get MinY value", "msMSSQL2008LayerGetExtent()");
return MS_FAILURE;
}

result_data[retLen] = 0;

extent->miny = atof(result_data);

rc = SQLGetData(layerinfo->conn->hstmt, 3, SQL_C_CHAR, result_data, sizeof(result_data), &retLen);
if (rc == SQL_ERROR) {
msSetError(MS_QUERYERR, "Failed to get MaxX value", "msMSSQL2008LayerGetExtent()");
return MS_FAILURE;
}

result_data[retLen] = 0;

extent->maxx = atof(result_data);

rc = SQLGetData(layerinfo->conn->hstmt, 4, SQL_C_CHAR, result_data, sizeof(result_data), &retLen);
if (rc == SQL_ERROR) {
msSetError(MS_QUERYERR, "Failed to get MaxY value", "msMSSQL2008LayerGetExtent()");
return MS_FAILURE;
}

result_data[retLen] = 0;

extent->maxy = atof(result_data);

return MS_SUCCESS;
}

/* Get the layer feature count */
Expand Down Expand Up @@ -1358,19 +1496,15 @@ static int prepare_database(layerObj *layer, rectObj rect, char **query_string)
}

/* adding spatial filter */
msMSSQL2008LayerGetExtent(layer, &extent);
if (rect.minx > extent.minx || rect.miny > extent.miny ||
rect.maxx < extent.maxx || rect.maxy < extent.maxy) {
if (hasFilter == MS_FALSE)
query = msStringConcatenate(query, " WHERE ");
else
query = msStringConcatenate(query, " AND ");
if (hasFilter == MS_FALSE)
query = msStringConcatenate(query, " WHERE ");
else
query = msStringConcatenate(query, " AND ");

query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".STIntersects(");
query = msStringConcatenate(query, box3d);
query = msStringConcatenate(query, ") = 1 ");
}
query = msStringConcatenate(query, layerinfo->geom_column);
query = msStringConcatenate(query, ".MakeValid().STIntersects(");
query = msStringConcatenate(query, box3d);
query = msStringConcatenate(query, ") = 1 ");

if (layerinfo->sort_spec)
query = msStringConcatenate(query, layerinfo->sort_spec);
Expand Down

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