Fix error when inserting to tables with datetime fields with QODBC

SQL Server 10 introduced stricter rules for TIMESTAMP validation,
making it necessary to specify the decimal digits.
Other databases might do the same as well, so this patch introduces
a check for the TIMESTAMP column size and adjusts the decimal digits
parameter as needed.

Task-number: QTBUG-2192

Change-Id: If6d798c6c928ebda75bc474e49a07fbbfbe5816c
Reviewed-by: Mark Brand <mabrand@mabrand.nl>
(cherry picked from qtbase/b8b79a0f37ec74fd5b4ad829e522a384ba3622ae)

1 files changed, 42 insertions, 4 deletions

diff --git a/src/sql/drivers/odbc/qsql_odbc.cpp b/src/sql/drivers/odbc/qsql_odbc.cpp
index 44c5f0ca5b..62ab8184a5 100644
--- a/src/sql/drivers/odbc/qsql_odbc.cpp
+++ b/src/sql/drivers/odbc/qsql_odbc.cpp
@@ -54,6 +54,7 @@
 #include <qstringlist.h>
 #include <qvarlengtharray.h>
 #include <qvector.h>
+#include <qmath.h>
 #include <QDebug>
 #include <QSqlQuery>
 
@@ -115,7 +116,7 @@ class QODBCDriverPrivate
 public:
     enum DefaultCase{Lower, Mixed, Upper, Sensitive};
     QODBCDriverPrivate()
-    : hEnv(0), hDbc(0), unicode(false), useSchema(false), disconnectCount(0), isMySqlServer(false),
+    : hEnv(0), hDbc(0), unicode(false), useSchema(false), disconnectCount(0), datetime_precision(19), isMySqlServer(false),
            isMSSqlServer(false), isFreeTDSDriver(false), hasSQLFetchScroll(true),
            hasMultiResultSets(false), isQuoteInitialized(false), quote(QLatin1Char('"'))
     {
@@ -127,6 +128,7 @@ public:
     bool unicode;
     bool useSchema;
     int disconnectCount;
+    int datetime_precision;
     bool isMySqlServer;
     bool isMSSqlServer;
     bool isFreeTDSDriver;
@@ -139,6 +141,7 @@ public:
     void checkHasSQLFetchScroll();
     void checkHasMultiResults();
     void checkSchemaUsage();
+    void checkDateTimePrecision();
     bool setConnectionOptions(const QString& connOpts);
     void splitTableQualifier(const QString &qualifier, QString &catalog,
                              QString &schema, QString &table);
@@ -1401,14 +1404,25 @@ bool QODBCResult::exec()
                 dt->hour = qdt.time().hour();
                 dt->minute = qdt.time().minute();
                 dt->second = qdt.time().second();
-                dt->fraction = qdt.time().msec() * 1000000;
+
+                int precision = d->driverPrivate->datetime_precision - 20; // (20 includes a separating period)
+                if (precision <= 0) {
+                    dt->fraction = 0;
+                } else {
+                    dt->fraction = qdt.time().msec() * 1000000;
+
+                    // (How many leading digits do we want to keep?  With SQL Server 2005, this should be 3: 123000000)
+                    int keep = (int)qPow(10.0, 9 - qMin(9, precision));
+                    dt->fraction /= keep * keep;
+                }
+
                 r = SQLBindParameter(d->hStmt,
                                       i + 1,
                                       qParamType[(QFlag)(bindValueType(i)) & QSql::InOut],
                                       SQL_C_TIMESTAMP,
                                       SQL_TIMESTAMP,
-                                      19,
-                                      0,
+                                      d->driverPrivate->datetime_precision,
+                                      precision,
                                       (void *) dt,
                                       0,
                                       *ind == SQL_NULL_DATA ? ind : NULL);
@@ -1895,6 +1909,7 @@ bool QODBCDriver::open(const QString & db,
     d->checkSqlServer();
     d->checkHasSQLFetchScroll();
     d->checkHasMultiResults();
+    d->checkDateTimePrecision();
     setOpen(true);
     setOpenError(false);
     if(d->isMSSqlServer) {
@@ -2130,6 +2145,29 @@ void QODBCDriverPrivate::checkHasMultiResults()
 #endif
 }
 
+void QODBCDriverPrivate::checkDateTimePrecision()
+{
+    SQLINTEGER columnSize;
+    SQLHANDLE hStmt;
+
+    SQLRETURN r = SQLAllocHandle(SQL_HANDLE_STMT, hDbc, &hStmt);
+    if (r != SQL_SUCCESS) {
+        return;
+    }
+
+    r = SQLGetTypeInfo(hStmt, SQL_TIMESTAMP);
+    if (r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO) {
+        r = SQLFetch(hStmt);
+        if ( r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO )
+        {
+            if (SQLGetData(hStmt, 3, SQL_INTEGER, &columnSize, sizeof(columnSize), 0) == SQL_SUCCESS) {
+                datetime_precision = (int)columnSize;
+            }
+        }
+    }
+    SQLFreeHandle(SQL_HANDLE_STMT, hStmt);
+}
+
 QSqlResult *QODBCDriver::createResult() const
 {
     return new QODBCResult(this, d);