The Ring programming language version 1.7 book - Part 32 of 196

Ring Documentation, Release 1.7
See "Write image file" + nl
write("testsgreat.jpg",hex2str( odbc_getdata(pODBC,3) ) )
ok
See "Close database..." + nl
odbc_disconnect(pODBC)
odbc_close(pODBC)
37.21. Save and Restore images 282

CHAPTER
THIRTYEIGHT
MYSQL FUNCTIONS
In this chapter we are going to learn about the MySQL functions provided by the Ring programming language.
• MySQL_Info()
• MySQL_Init()
• MySQL_Error()
• MySQL_Connect()
• MySQL_Close()
• MySQL_Query()
• MySQL_Insert_ID()
• MySQL_Result()
• MySQL_Next_Result()
• MySQL_Columns()
• MySQL_Result2()
• MySQL_Escape_String()
• MySQL_AutoCommit()
• MySQL_Commit()
• MySQL_Rollback()
Before using the next function load the mysqllib.ring library
load "mysqllib.ring"
# Use MySQL functions
38.1 MySQL_Info() Function
We can get the MySQL Client version using the MySQL_Info() function.
Syntax:
MySQL_Info() ---> string contains the MySQL Client version
Example:
see "MySQL Client Version : " + mysql_info()
283

Output:
MySQL Client Version : 6.1.5
38.2 MySQL_Init() Function
We can start using MySQL Client through the MySQL_Init() function.
Syntax:
MySQL_Init() ---> MySQL Handle
38.3 MySQL_Error() Function
We can get the error message from the MySQL Client using the MySQL_Error() function.
Syntax:
MySQL_Error(MySQL Handle) ---> Error message as string
38.4 MySQL_Connect() Function
We can connect to the MySQL database server using the MySQL_Connect() function.
Syntax:
MySQL_Connect(MySQL Handle, cServer, cUserName, cPassword) ---> lStatus
38.5 MySQL_Close() Function
We can close the connection to the MySQL database using the MySQL_Close() function
Syntax:
MySQL_Close(MySQL Handle)
38.6 MySQL_Query() Function
We can execute SQL queries using the MySQL_Query() function
Syntax:
MySQL_Query(MySQL Handle, cSQLQuery)
38.2. MySQL_Init() Function 284

38.7 Create Database
The next example connect to MySQL Server then create new database.
See "MySQL Test - Create Database" + nl
con = mysql_init()
See "Connect" + nl
if mysql_connect(con,"localhost","root","root") = 0
see "Cann't connect" + nl
see "Error : " + mysql_error(con) + nl
mysql_close(con)
bye
ok
See "Create Database..." + nl
mysql_query(con,"CREATE DATABASE mahdb")
See "Close Connection" + nl
mysql_close(con)
Output:
MySQL Test - Create Database
Connect
Create Database...
Close Connection
38.8 Create Table and Insert Data
The next example create new table and insert records
func main
see "Create Table and Insert Records" + nl
con = mysql_init()
see "Connect" + nl
if mysql_connect(con, "localhost", "root", "root","mahdb") = 0
system_error(con)
ok
see "Drop table" + nl
if mysql_query(con, "DROP TABLE IF EXISTS Employee") system_error(con) ok
see "Create table" + nl
if mysql_query(con, "CREATE TABLE Employee(Id INT, Name TEXT, Salary INT)")
system_error(con) ok
see "Insert data" + nl
if mysql_query(con, "INSERT INTO Employee VALUES(1,'Mahmoud',15000)")
if mysql_query(con, "INSERT INTO Employee VALUES(2,'Samir',16000)")
if mysql_query(con, "INSERT INTO Employee VALUES(3,'Fayed',17000)")
38.7. Create Database 285

see "Close connection" + nl
mysql_close(con)
func system_error con
see mysql_error(con) mysql_close(con) bye
Output:
Create Table and Insert Records
Connect
Drop table
Create table
Insert data
Close connection
38.9 MySQL_Insert_ID() Function
We can get the inserted row id using the MySQL_Insert_ID() function
Syntax:
MySQL_Insert_ID() ---> Inserted row id as number
Example:
con = mysql_init()
see "connect to database" + nl
mysql_connect(con,"localhost","root","root","mahdb")
see "drop table" + nl
mysql_query(con, "DROP TABLE IF EXISTS Customers")
see "create table" + nl
mysql_query(con, "CREATE TABLE Customers(Id INT PRIMARY KEY AUTO_INCREMENT, Name TEXT)")
see "insert record" + nl
mysql_query(con, "INSERT INTO Customers(Name) VALUES('Mahmoud')")
mysql_query(con, "INSERT INTO Customers(Name) VALUES('Samir')")
mysql_query(con, "INSERT INTO Customers(Name) VALUES('Fayed')")
mysql_query(con, "INSERT INTO Customers(Name) VALUES('Test 2015')")
see "inserted row id : " + mysql_insert_id(con) + nl
see "close database" + nl
mysql_close(con)
Output:
connect to database
drop table
create table
insert record
insert record
insert record
insert record
inserted row id : 4
close database
38.9. MySQL_Insert_ID() Function 286

38.10 MySQL_Result() Function
We can get the query result (data without column names) using the MySQL_Result() function.
Syntax:
MySQL_Result(MySQL Handle) ---> List contains the query result
38.11 MySQL_Next_Result() Function
We can move to the next query result using the MySQL_Next_Result() function. We use this function when we have
multiple SQL statements in the same query.
Syntax:
MySQL_Next_Result(MySQL Handle)
38.12 Print Query Result
The next example execute a query on the database then print the result.
con = mysql_init()
see "Connect to database" + nl
mysql_connect(con, "localhost", "root", "root","mahdb")
see "Execute Query" + nl
mysql_query(con, "SELECT Name FROM Employee WHERE Id=1;"+
"SELECT Name FROM Employee WHERE Id=3")
see "Print Result" + nl
see mysql_result(con)
mysql_next_result(con)
see mysql_result(con)
see "close database" + nl
mysql_close(con)
Output:
Connect to database
Execute Query
Print Result
Mahmoud
Fayed
close database
38.13 MySQL_Columns() Function
We can get a list of columns names using the MySQL_Columns() function.
Syntax:
38.10. MySQL_Result() Function 287

MySQL_Columns(MySQL Handle) ---> List contains columns information
Example:
con = mysql_init()
mysql_query(con, "SELECT * FROM Employee")
see "Result" + nl
see mysql_columns(con)
see "Close database" + nl
mysql_close(con)
Output:
Connect to database
Execute Query
Result
Id
11
3
32768
Name
65535
252
16
Salary
11
3
32768
Close database
38.14 MySQL_Result2() Function
Instead of using MySQL_Result() to get the result data without columns names, we can use the MySQL_Result2() to
get all of the column names then the query result in one list.
Syntax:
MySQL_Result2(MySQL Handle) ---> List (query result starts with columns names)
Example:
con = mysql_init()
mysql_query(con, "SELECT * FROM Employee")
see "Print Result" + nl
see mysql_result2(con)
see "Close database" + nl
mysql_close(con)
Output:
38.14. MySQL_Result2() Function 288

Connect to database
Execute Query
Print Result
Id
Name
Salary
1
Mahmoud
15000
2
Samir
16000
3
Fayed
17000
Close database
38.15 MySQL_Escape_String() Function
We can store binary data and special characters in the database after processing using MySQL_Escape_String() func-
tion
Syntax:
MySQL_Escape_String(MySQL Handle, cString) ---> String after processing
38.16 Save Image inside the database
Example:
See "Read file" + nl
cFile = read("testsmahmoud.jpg")
con = mysql_init()
See "Connect to database..." + nl
See "Escape string..." + nl
cFile = mysql_escape_string(con,cFile)
stmt = "INSERT INTO photo(id, data) VALUES(1, '" + cFile + "')"
See "Insert data..." + nl
mysql_query(con,stmt)
mysql_close(con)
Output:
Read file
Connect to database...
Escape string...
Insert data...
Close database...
38.15. MySQL_Escape_String() Function 289

38.17 Restore Image From The Database
Example:
con = mysql_init()
See "Connect to database..." + nl
See "Read data from database..." + nl
mysql_query(con,"SELECT data FROM photo WHERE id=1")
See "Write new file" + nl
result = mysql_result(con)
write("testsmahmoud2.jpg",result[1][1])
mysql_close(con)
Output:
Connect to database...
Read data from database...
Write new file
Close database...
38.18 MySQL_AutoCommit() Function
We can enable or disable the auto commit feature using the MySQL_AutoCommit() function.
Syntax:
MySQL_AutoCommit(MySQL Handle, lStatus) # lstatus can be True/False
38.19 MySQL_Commit() Function
We can commit updates to the database using the MySQL_Commit() function.
Syntax:
MySQL_Commit(MySQL Handle)
38.20 MySQL_Rollback() Function
We can rollback updates to the database using the MySQL_Rollback() function.
Syntax:
MySQL_Rollback(MySQL Handle)
38.21 Transaction Example
The next example presents the usage of MySQL_Autocommit(), MySQL_Commit() & MySQL_RollBack() functions.
Example:
38.17. Restore Image From The Database 290

func main
con = mysql_init()
see "Connect" + nl
if mysql_connect(con, "localhost", "root", "root","mahdb") = 0
see "Drop table" + nl
if mysql_query(con, "DROP TABLE IF EXISTS Employee2")
see "Create table" + nl
if mysql_query(con, "CREATE TABLE Employee2(Id INT, Name TEXT, Salary INT)")
see "Insert data" + nl
if mysql_query(con, "INSERT INTO Employee2 VALUES(1,'Mahmoud',15000)")
if mysql_query(con, "INSERT INTO Employee2 VALUES(2,'Samir',16000)")
if mysql_query(con, "INSERT INTO Employee2 VALUES(3,'Fayed',17000)")
mysql_autocommit(con,False)
mysql_query(con, "INSERT INTO Employee2 VALUES(4,'Ahmed',5000)")
mysql_query(con, "INSERT INTO Employee2 VALUES(5,'Ibrahim',50000)")
mysql_query(con, "INSERT INTO Employee2 VALUES(6,'Mohammed',50000)")
See "Save transaction (y/n) " give nChoice
if upper(nChoice) = "Y"
mysql_commit(con)
else
mysql_rollback(con)
ok
see "Close connection" + nl
mysql_close(con)
func system_error con
see mysql_error(con)
mysql_close(con)
bye
Output:
Connect
Drop table
Create table
Insert data
Save transaction (y/n) y
Close connection
38.21. Transaction Example 291

The Ring programming language version 1.7 book - Part 32 of 196

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The Ring programming language version 1.7 book - Part 32 of 196