bank

sqlite/examples/bank/out.out

@@ -0,0 +1,20 @@
+Jane|0
+Mary|1000
+Ann|1000
+Total|2000
+-----
+Jane|100
+Mary|900
+Ann|1000
+Total|2000
+-----
+Jane|100
+Mary|800
+Ann|1000
+Total|1900
+-----
+Jane|100
+Mary|800
+Ann|1000
+Total|1900
+-----

sqlite/examples/bank/setup_bank.sql

@@ -0,0 +1,10 @@
+CREATE TABLE bank (
+    name TEXT PRIMARY KEY,
+    balance INTEGER NOT NULL
+);
+
+INSERT INTO bank (name, balance) VALUES ("Jane", 0);
+INSERT INTO bank (name, balance) VALUES ("Mary", 1000);
+INSERT INTO bank (name, balance) VALUES ("Ann", 1000);
+
+

sqlite/examples/bank/show.sql

@@ -0,0 +1,3 @@
+SELECT * FROM bank;
+SELECT "Total", SUM(balance) FROM bank;
+SELECT "-----";

sqlite/examples/bank/steps.sh

@@ -0,0 +1,13 @@
+sqlite3 bank.db < setup_bank.sql
+sqlite3 bank.db < show.sql
+
+sqlite3 bank.db < transfer.sql
+sqlite3 bank.db < show.sql
+
+sqlite3 bank.db < without_transaction.sql
+sqlite3 bank.db < show.sql
+
+sqlite3 bank.db < with_transaction.sql
+sqlite3 bank.db < show.sql
+
+rm -f bank.db

sqlite/examples/bank/transfer.sql

@@ -0,0 +1,3 @@
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Mary") - 100 WHERE name = "Mary";
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Jane") + 100 WHERE name = "Jane";
+

sqlite/examples/bank/with_transaction.sql

@@ -0,0 +1,5 @@
+BEGIN TRANSACTION;
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Mary") - 100 WHERE name = "Mary";
+.exit
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Jane") + 100 WHERE name = "Jane";
+COMMIT;

sqlite/examples/bank/without_transaction.sql

@@ -0,0 +1,4 @@
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Mary") - 100 WHERE name = "Mary";
+.exit
+UPDATE bank SET balance = (SELECT balance FROM bank WHERE name = "Jane") + 100 WHERE name = "Jane";
+

sqlite/intro.md

@@ -163,10 +163,6 @@ Meaning of life?|42
 
 ![](examples/foreign-key.sql)
 
-## Transactions
-{id: transactions}
-
-![](examples/transaction.sql)
 
 ## PRAGMA
 {id: pragma}
@@ -179,10 +175,29 @@ Meaning of life?|42
 ![](examples/update.sql)
 
 
+## SQLite Transaction - in a bank
+{id: sqlite-transactions-in-a-bank}
+
+* Setup Bank accounts with some initial money.
+* Move some money from one account to another - two separate steps. Worked.
+* Move some money from one account to another - two separate steps - stop in the middle. Failed.
+* Move some money from one account to another - Transaction - stop in the middle. Worked. (money stayed where it was)
+* Remove bank
+
+![](examples/bank/setup_bank.sql)
+![](examples/bank/show.sql)
+![](examples/bank/transfer.sql)
+![](examples/bank/without_transaction.sql)
+![](examples/bank/with_transaction.sql)
+
+![](examples/bank/steps.sh)
+
+![](examples/bank/out.out)
+
 
 
 * TODO: loading a large CSV file into the database and running queries.
-* TODO: creating a multi-tabe databas, dumping it and then loading it and running queries against it.
+* TODO: creating a multi-tabe database, dumping it and then loading it and running queries against it.
 * TODO: FOREIGN KEY - cascading deletition?