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When you execute an SQL operation on a Session using the
sql() method, an SqlResult
is returned. Iterating over an SqlResult is
identical to working with results from CRUD operations. The
following example assumes that the users table exists.
MySQL Shell JavaScript Code
var res = mySession.sql('SELECT name, age FROM users').execute();
var row;
while (row = res.fetchOne()) {
print('Name: ' + row['name'] + '\n');
print(' Age: ' + row.age + '\n');
}MySQL Shell Python Code
res = mySession.sql('SELECT name, age FROM users').execute()
row = res.fetch_one()
while row:
print('Name: %s\n' % row[0])
print(' Age: %s\n' % row.age)
row = res.fetch_one()Node.js JavaScript Code
mySession.sql('SELECT name, age FROM users')
.execute()
.then(res => {
while (row = res.fetchOne()) {
console.log('Name: ' + row[0] + '\n');
console.log(' Age: ' + row[1] + '\n');
}
});Alternatively, you can use callbacks:
mySession.sql('SELECT name, age FROM users')
.execute(function (row) {
console.log('Name: ' + row[0] + '\n');
console.log(' Age: ' + row[1] + '\n');
});C# Code
var res = Session.SQL("SELECT name, age FROM users").Execute();
while (res.Next())
{
Console.WriteLine("Name: " + res.Current["name"]);
Console.WriteLine("Age: " + res.Current["age"]);
}Python Code
# Connector/Python
res = mySession.sql('SELECT name, age FROM users').execute()
row = res.fetch_one()
while row:
print('Name: %s\n' % row[0])
print(' Age: %s\n' % row.age)
row = res.fetch_one()Java Code
SqlResult res = mySession.sql("SELECT name, age FROM users").execute();
Row row;
while ((row = res.fetchOne()) != null) {
System.out.println(" Name: " + row.getString("name") + "\n");
System.out.println(" Age: " + row.getInt("age") + "\n");
}C++ Code
SqlResult res = mysession.sql("SELECT name, age FROM users").execute();
Row row;
while ((row = res.fetchOne())) {
cout << "Name: " << row[0] << endl;
cout << " Age: " << row[1] << endl;
}
SqlResult differs from results returned by CRUD
operations in the way how result sets and data sets are
represented. An SqlResult combines a result set
produced by, for example, INSERT,
and a data set, produced by, for example,
SELECT in one. Unlike with CRUD
operations, there is no distinction between the two types for
SqlResult. An SqlResult
instance exports methods for accessing data and to retrieving the
last inserted ID or number of affected rows.
Use the hasData() method to learn whether an
SqLResult is a data set or a result. The method
is useful when code is to be written that has no knowledge about
the origin of an SqlResult. This can be the
case when writing a generic application function to print query
results or when processing stored procedure results. If
hasData() returns true, then
the SqlResult origins from a
SELECT or similar command that can
return rows.
A return value of true does not indicate
whether the data set contains any rows. The data set can be empty
if, for example, fetchOne() returns
NULL or fetchAll() returns
an empty list. And if multiple result sets are returned, any of
the result sets may be empty too. The following example assumes
that the procedure my_proc exists.
MySQL Shell JavaScript Code
var res = mySession.sql('CALL my_proc()').execute();
if (res.hasData()){
var row = res.fetchOne();
if (row){
print('List of rows available for fetching.');
do {
print(row);
} while (row = res.fetchOne());
}
else{
print('Empty list of rows.');
}
}
else {
print('No row result.');
}MySQL Shell Python Code
res = mySession.sql('CALL my_proc()').execute()
if res.has_data():
row = res.fetch_one()
if row:
print('List of rows available for fetching.')
while row:
print(row)
row = res.fetch_one()
else:
print('Empty list of rows.')
else:
print('No row result.')Node.js JavaScript Code
mySession.sql('CALL my_proc()')
.execute()
.then(function (res) {
if (!res.hasData()) {
return console.log('No row result.');
}
var row = res.fetchOne();
if (!row) {
return console.log('Empty list of rows.');
}
console.log('List of rows available for fetching.');
do {
console.log(row);
} while (row = res.fetchOne());
})C# Code
var res = Session.SQL("CALL my_proc()").Execute();
if (res.HasData)
{
var row = res.FetchOne();
if (row != null)
{
Console.WriteLine("List of rows available for fetching.");
do
{
PrintResult(row);
} while ((row = res.FetchOne()) != null);
}
else
{
Console.WriteLine("Empty list of rows.");
}
}
else
{
Console.WriteLine("No row result.");
}Python Code
# Connector/Python
res = mySession.sql('CALL my_proc()').execute()
if res.has_data():
row = res.fetch_one()
if row:
print('List of rows available for fetching.')
while row:
print(row)
row = res.fetch_one()
else:
print('Empty list of rows.')
else:
print('No row result.')Java Code
SqlResult res = mySession.sql("CALL my_proc()").execute();
if (res.hasData()){
Row row = res.fetchOne();
if (row != null){
System.out.println("List of rows available for fetching.");
do {
for (int c = 0; c < res.getColumnCount(); c++) {
System.out.println(row.getString(c));
}
} while ((row = res.fetchOne()) != null);
}
else{
System.out.println("Empty list of rows.");
}
}
else {
System.out.println("No row result.");
}C++ Code
SqlResult res = mysession.sql("CALL my_proc()").execute();
if (res.hasData())
{
Row row = res.fetchOne();
if (row)
{
cout << "List of rows available for fetching." << endl;
do {
cout << "next row: ";
for (unsigned i=0 ; i < row.colCount(); ++i)
cout << row[i] << ", ";
cout << endl;
} while ((row = res.fetchOne()));
}
else
{
cout << "Empty list of rows." << endl;
}
}
else
{
cout << "No row result." << endl;
}
It is an error to call either fetchOne() or
fetchAll() when hasData()
indicates that an SqlResult is not a data set.
MySQL Shell JavaScript Code
function print_result(res) {
if (res.hasData()) {
// SELECT
var columns = res.getColumns();
var record = res.fetchOne();
while (record){
for (index in columns){
print (columns[index].getColumnName() + ": " + record[index] + "\n");
}
// Get the next record
record = res.fetchOne();
}
} else {
// INSERT, UPDATE, DELETE, ...
print('Rows affected: ' + res.getAffectedItemsCount());
}
}
print_result(mySession.sql('DELETE FROM users WHERE age < 30').execute());
print_result(mySession.sql('SELECT * FROM users WHERE age = 40').execute());MySQL Shell Python Code
def print_result(res):
if res.has_data():
# SELECT
columns = res.get_columns()
record = res.fetch_one()
while record:
index = 0
for column in columns:
print("%s: %s \n" % (column.get_column_name(), record[index]))
index = index + 1
# Get the next record
record = res.fetch_one()
else:
#INSERT, UPDATE, DELETE, ...
print('Rows affected: %s' % res.get_affected_items_count())
print_result(mySession.sql('DELETE FROM users WHERE age < 30').execute())
print_result(mySession.sql('SELECT * FROM users WHERE age = 40').execute())Node.js JavaScript Code
function print_result(res) {
if (res.hasData()) {
// SELECT
var columns = res.getColumns();
var record = res.fetchOne();
while (record) {
for (index in columns) {
console.log(columns[index].getColumnName() + ": " + record[index]);
}
// Get the next record
record = res.fetchOne();
}
} else {
// INSERT, UPDATE, DELETE, ...
console.log('Rows affected: ' + res.getAffectedItemsCount());
}
}
mySession.sql(`DELETE FROM users WHERE age < 30`)
.execute()
.then(function (res) {
print_result(res);
});
mySession.sql(`SELECT * FROM users WHERE age = 40`)
.execute()
.then(function (res) {
print_result(res);
});C# Code
private void print_result(SqlResult res)
{
if (res.HasData)
{
// SELECT
}
else
{
// INSERT, UPDATE, DELETE, ...
Console.WriteLine("Rows affected: " + res.RecordsAffected);
}
}
print_result(Session.SQL("DELETE FROM users WHERE age < 30").Execute());
print_result(Session.SQL("SELECT COUNT(*) AS forty FROM users WHERE age = 40").Execute());Python Code
# Connector/Python
def print_result(res):
if res.has_data():
# SELECT
columns = res.get_columns()
record = res.fetch_one()
while record:
index = 0
for column in columns:
print("%s: %s \n" % (column.get_column_name(), record[index]))
index = index + 1
# Get the next record
record = res.fetch_one()
else:
#INSERT, UPDATE, DELETE, ...
print('Rows affected: %s' % res.get_affected_items_count())
print_result(mySession.sql('DELETE FROM users WHERE age < 30').execute())
print_result(mySession.sql('SELECT * FROM users WHERE age = 40').execute())Java Code
private void print_result(SqlResult res) {
if (res.hasData()) {
// SELECT
Row row;
while ((row = res.fetchOne()) != null){
for (int c = 0; c < res.getColumnCount(); c++) {
System.out.println(row.getString(c));
}
}
} else {
// INSERT, UPDATE, DELETE, ...
System.out.println("Rows affected: " + res.getAffectedItemsCount());
}
}
print_result(mySession.sql("DELETE FROM users WHERE age < 30").execute());
print_result(mySession.sql("SELECT COUNT(*) AS forty FROM users WHERE age = 40").execute());C++ Code
void print_result(SqlResult &&_res)
{
// Note: We need to store the result somewhere to be able to process it.
SqlResult res(std::move(_res));
if (res.hasData())
{
// SELECT
const Columns &columns = res.getColumns();
Row record = res.fetchOne();
while (record)
{
for (unsigned index=0; index < res.getColumnCount(); ++index)
{
cout << columns[index].getColumnName() << ": "
<< record[index] << endl;
}
// Get the next record
record = res.fetchOne();
}
}
else
{
// INSERT, UPDATE, DELETE, ...
// Note: getAffectedItemsCount() not yet implemented in Connector/C++.
cout << "No rows in the result" << endl;
}
}
print_result(mysession.sql("DELETE FROM users WHERE age < 30").execute());
print_result(mysession.sql("SELECT * FROM users WHERE age = 40").execute());
Calling a stored procedure might result in having to deal with
multiple result sets as part of a single execution. As a result
for the query execution an SqlResult object is
returned, which encapsulates the first result set. After
processing the result set you can call
nextResult() to move forward to the next
result, if there is any. Once you advanced to the next result set,
it replaces the previously loaded result which then becomes
unavailable.
MySQL Shell JavaScript Code
function print_result(res) {
if (res.hasData()) {
// SELECT
var columns = res.getColumns();
var record = res.fetchOne();
while (record){
for (index in columns){
print (columns[index].getColumnName() + ": " + record[index] + "\n");
}
// Get the next record
record = res.fetchOne();
}
} else {
// INSERT, UPDATE, DELETE, ...
print('Rows affected: ' + res.getAffectedItemsCount());
}
}
var res = mySession.sql('CALL my_proc()').execute();
// Prints each returned result
var more = true;
while (more){
print_result(res);
more = res.nextResult();
}MySQL Shell Python Code
def print_result(res):
if res.has_data():
# SELECT
columns = res.get_columns()
record = res.fetch_one()
while record:
index = 0
for column in columns:
print("%s: %s \n" % (column.get_column_name(), record[index]))
index = index + 1
# Get the next record
record = res.fetch_one()
else:
#INSERT, UPDATE, DELETE, ...
print('Rows affected: %s' % res.get_affected_items_count())
res = mySession.sql('CALL my_proc()').execute()
# Prints each returned result
more = True
while more:
print_result(res)
more = res.next_result()Node.js JavaScript Code
function print_result(res) {
if (res.hasData()) {
// SELECT
var columns = res.getColumns();
var record = res.fetchOne();
while (record) {
for (index in columns) {
console.log(columns[index].getColumnName() + ": " + record[index]);
}
// Get the next record
record = res.fetchOne();
}
} else {
// INSERT, UPDATE, DELETE, ...
console.log('Rows affected: ' + res.getAffectedItemsCount());
}
}
mySession.sql('CALL my_proc()')
.execute()
.then(function (res) {
// Prints each returned result
var more = true;
while (more) {
print_result(res);
more = res.nextResult();
}
})C# Code
var res = Session.SQL("CALL my_proc()").Execute();
if (res.HasData)
{
do
{
Console.WriteLine("New resultset");
while (res.Next())
{
Console.WriteLine(res.Current);
}
} while (res.NextResult());
}Python Code
# Connector/Python
def print_result(res):
if res.has_data():
# SELECT
columns = res.get_columns()
record = res.fetch_one()
while record:
index = 0
for column in columns:
print("%s: %s \n" % (column.get_column_name(), record[index]))
index = index + 1
# Get the next record
record = res.fetch_one()
else:
#INSERT, UPDATE, DELETE, ...
print('Rows affected: %s' % res.get_affected_items_count())
res = mySession.sql('CALL my_proc()').execute()
# Prints each returned result
more = True
while more:
print_result(res)
more = res.next_result()Java Code
SqlResult res = mySession.sql("CALL my_proc()").execute();C++ Code
SqlResult res = mysession.sql("CALL my_proc()").execute();
while (true)
{
if (res.hasData())
{
cout << "List of rows in the resultset." << endl;
for (Row row; (row = res.fetchOne());)
{
cout << "next row: ";
for (unsigned i = 0; i < row.colCount(); ++i)
cout << row[i] << ", ";
cout << endl;
}
}
else
{
cout << "No rows in the resultset." << endl;
}
if (!res.nextResult())
break;
cout << "Next resultset." << endl;
}
When using Node.js, individual rows can be returned immediately
using a callback, which has to be provided to the
execute() method. To identify individual result
sets you can provide a second callback, which is called for meta
data that marks the beginning of a result set.
Node.js JavaScript Code
var resultcount = 0;
var res = session
.sql('CALL my_proc()')
.execute(
function (row) {
console.log(row);
},
function (meta) {
console.log('Begin of result set number ', resultCount++);
});The number of result sets is not known immediately after the query execution. Query results can be streamed to the client or buffered at the client. In the streaming or partial buffering mode a client cannot tell whether a query emits more than one result set.