HackBase/python-cx_Oracle
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix cursor.scroll() to calculate row count correctly in all situations and

Browse Source 
add test cases to verify that it does in fact work.
This commit is contained in:
Anthony Tuininga 2017-01-12 15:22:29 -07:00
parent 0e50be2a08
commit ab42359f26
2 changed files with 70 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
Cursor.c
View File

@ -26,6 +26,7 @@ typedef struct {
int outputSize;
int outputSizeColumn;
ub8 rowCount;
ub8 bufferMinRow;
ub4 bufferRowCount;
ub4 bufferRowIndex;
int statementType;
@ -552,8 +553,9 @@ static int Cursor_SetRowCount(
self->rowCount = 0;
self->hasRowsToFetch = 0;
if (self->statementType == OCI_STMT_SELECT) {
self->bufferMinRow = 0;
self->bufferRowCount = 0;
self->bufferRowIndex = self->fetchArraySize;
self->bufferRowIndex = 0;
self->hasRowsToFetch = 1;
} else if (self->statementType == OCI_STMT_INSERT ||
self->statementType == OCI_STMT_UPDATE ||
@ -1913,7 +1915,8 @@ static int Cursor_InternalFetch(
"Cursor_InternalFetch(): get rows fetched") < 0)
return -1;
// reset buffer row index
// set buffer row info
self->bufferMinRow = self->rowCount + 1;
self->bufferRowIndex = 0;
return 0;
@ -2099,8 +2102,8 @@ static PyObject *Cursor_Scroll(
PyObject *keywordArgs) // keyword arguments
{
static char *keywordList[] = { "value", "mode", NULL };
ub8 desiredRow, minRowInBuffers, maxRowInBuffers;
ub4 fetchMode, numRows, currentPosition;
ub8 desiredRow;
sword status;
char *mode;
int value;
@ -2113,12 +2116,10 @@ static PyObject *Cursor_Scroll(
return NULL;
// validate mode
if (!mode) {
fetchMode = OCI_FETCH_RELATIVE;
desiredRow = self->rowCount + value;
} else if (strcmp(mode, "relative") == 0) {
if (!mode || strcmp(mode, "relative") == 0) {
fetchMode = OCI_FETCH_RELATIVE;
desiredRow = self->rowCount + value;
value = desiredRow - (self->bufferMinRow + self->bufferRowCount - 1);
} else if (strcmp(mode, "absolute") == 0) {
fetchMode = OCI_FETCH_ABSOLUTE;
desiredRow = value;
@ -2139,19 +2140,11 @@ static PyObject *Cursor_Scroll(
return NULL;
// determine if a fetch is actually required; "last" is always fetched
if (fetchMode != OCI_FETCH_LAST && self->bufferRowCount > 0) {
minRowInBuffers = self->rowCount - self->bufferRowIndex;
maxRowInBuffers = self->rowCount + self->bufferRowCount -
self->bufferRowIndex - 1;
if (self->bufferRowIndex == self->bufferRowCount) {
minRowInBuffers += 1;
maxRowInBuffers += 1;
}
if (desiredRow >= minRowInBuffers && desiredRow <= maxRowInBuffers) {
self->bufferRowIndex = desiredRow - minRowInBuffers;
self->rowCount = desiredRow - 1;
Py_RETURN_NONE;
}
if (fetchMode != OCI_FETCH_LAST && desiredRow >= self->bufferMinRow &&
desiredRow < self->bufferMinRow + self->bufferRowCount) {
self->bufferRowIndex = desiredRow - self->bufferMinRow;
self->rowCount = desiredRow - 1;
Py_RETURN_NONE;
}
// perform fetch; when fetching the last row, only fetch a single row
@ -2160,21 +2153,12 @@ static PyObject *Cursor_Scroll(
status = OCIStmtFetch2(self->handle, self->environment->errorHandle,
numRows, fetchMode, value, OCI_DEFAULT);
Py_END_ALLOW_THREADS
if (status == OCI_NO_DATA) {
if (fetchMode == OCI_FETCH_FIRST || fetchMode == OCI_FETCH_LAST) {
self->hasRowsToFetch = 0;
self->rowCount = 0;
self->bufferRowCount = 0;
self->bufferRowIndex = 0;
} else {
PyErr_SetString(PyExc_IndexError,
"requested scroll operation would leave result set");
return NULL;
}
} else if (Environment_CheckForError(self->environment, status,
if (status == OCI_NO_DATA || fetchMode == OCI_FETCH_LAST)
self->hasRowsToFetch = 0;
else if (Environment_CheckForError(self->environment, status,
"Cursor_Scroll(): fetch") < 0)
return NULL;
self->hasRowsToFetch = 1;
else self->hasRowsToFetch = 1;
// determine the number of rows actually fetched
status = OCIAttrGet(self->handle, OCI_HTYPE_STMT, &self->bufferRowCount, 0,
@ -2183,6 +2167,20 @@ static PyObject *Cursor_Scroll(
"Cursor_Scroll(): get rows fetched") < 0)
return NULL;
// handle the case when no rows have been retrieved
if (self->bufferRowCount == 0) {
if (fetchMode != OCI_FETCH_FIRST && fetchMode != OCI_FETCH_LAST) {
PyErr_SetString(PyExc_IndexError,
"requested scroll operation would leave result set");
return NULL;
}
self->rowCount = 0;
self->bufferMinRow = 0;
self->bufferRowCount = 0;
self->bufferRowIndex = 0;
Py_RETURN_NONE;
}
// determine the current position of the cursor
status = OCIAttrGet(self->handle, OCI_HTYPE_STMT, &currentPosition, 0,
OCI_ATTR_CURRENT_POSITION, self->environment->errorHandle);
@ -2192,8 +2190,8 @@ static PyObject *Cursor_Scroll(
// reset buffer row index and row count
self->rowCount = currentPosition - self->bufferRowCount;
self->bufferMinRow = self->rowCount + 1;
self->bufferRowIndex = 0;
Py_RETURN_NONE;
}

38
test/Cursor.py
View File

@ -381,6 +381,44 @@ class TestCursor(BaseTestCase):
self.assertEqual(row[0], 3.75)
self.assertEqual(cursor.rowcount, 3)
def testScrollNoRows(self):
"""test scrolling when there are no rows"""
self.cursor.execute("truncate table TestTempTable")
cursor = self.connection.cursor(scrollable = True)
cursor.execute("select * from TestTempTable")
cursor.scroll(mode = "last")
self.assertEqual(cursor.fetchall(), [])
cursor.scroll(mode = "first")
self.assertEqual(cursor.fetchall(), [])
self.assertRaises(IndexError, cursor.scroll, 1, mode = "absolute")
def testScrollDifferingArrayAndFetchSizes(self):
"""test scrolling with differing array sizes and fetch array sizes"""
self.cursor.execute("truncate table TestTempTable")
for i in range(30):
self.cursor.execute("insert into TestTempTable values (:1, null)",
(i + 1,))
for arraySize in range(1, 6):
cursor = self.connection.cursor(scrollable = True)
cursor.arraysize = arraySize
cursor.execute("select IntCol from TestTempTable order by IntCol")
for numRows in range(1, arraySize + 1):
cursor.scroll(15, "absolute")
rows = cursor.fetchmany(numRows)
self.assertEqual(rows[0][0], 15)
self.assertEqual(cursor.rowcount, 15 + numRows - 1)
cursor.scroll(9)
rows = cursor.fetchmany(numRows)
numRowsFetched = len(rows)
self.assertEqual(rows[0][0], 15 + numRows + 8)
self.assertEqual(cursor.rowcount,
15 + numRows + numRowsFetched + 7)
cursor.scroll(-12)
rows = cursor.fetchmany(numRows)
self.assertEqual(rows[0][0], 15 + numRows + numRowsFetched - 5)
self.assertEqual(cursor.rowcount,
15 + numRows + numRowsFetched + numRows - 6)
def testSetInputSizesMultipleMethod(self):
"""test setting input sizes with both positional and keyword args"""
self.assertRaises(cx_Oracle.InterfaceError,