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HAP 709 – Healthcare Databases. SQL Data Manipulation Language (DML) Updated Fall, 2009. SQL Components. SQL. DCL. DDL. DML. Data I/O. RDBMS Structure. DBA Activities. C reate Record. Create/Delete DBs. Create Users. R ead Record. Delete Users. Create/Delete Tables.
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HAP 709 – Healthcare Databases SQL Data Manipulation Language (DML) Updated Fall, 2009
SQL Components SQL DCL DDL DML Data I/O RDBMS Structure DBA Activities Create Record Create/Delete DBs Create Users Read Record Delete Users Create/Delete Tables Grant privileges Update Record Alter Tables Implement AccessSecurity Delete Record
SQL manipulates entire column of data No need to repeat the commands for each record
SQL is non-procedural You do not need to tell the computer how to do the tasks. All you need to tell the computer is what you want to see and the computer will figure out how to produce the results you want to see
Typical Commands • Details of commands are provided online. Here we review a select few commands • Key words are reserved for command specifications. These words cannot be used as names for fields or tables.
Data Type Must be Specified • Number • Integer, Small integer, Big integer, Numeric data (with fraction), Decimal (with precision) • String • Character, Large character, National character • Boolean • Date/times • Date, Time with and without time zone, Timestamp with and without time zone • Intervals
Data Manipulation Commands • Combined numeric values • Calculate intervals among dates/times • Process a series of Boolean statements • Concatenate strings together
Logical Connectives • Allows you to build complex predicates out of simple ones • Set functions • Count, Max, Min, Sum, Avg, Stdev • Sub-queries
Using SQL with Microsoft Access • Open database and select queries from objects • Select create query in design view • Add tables and close add tables button • Choose SQL view • Delete the select statement and enter commands you want • When finished save and enter a name for the query
INSERT INTO Syntax INSERT INTO <myTable> VALUES (<Field1> <DataType>, <Field2> <DataType>,…);
INSERT INTO Syntax INSERT INTO <myTable> VALUES (<Field1> <DataType>, <Field2> <DataType>,…); INSERT INTO PAT VALUES(983883,'JOHN','MARTINEZ');
INSERT INTO in MS Access Note: In MS Access the INSERT INTO is called an Append Query
UPDATE Statement (1) UPDATE <myTable> SET <Field1> = <Value1> WHERE {condition};
UPDATE Statement (1) UPDATE <myTable> SET <Field1> = <Value1> WHERE {condition}; UPDATE PAT SET PAT_FNM = 'JOHNNY' WHERE PAT_ID = 983883;
Updating Multiple Records(1) A new field needs to be populated after modification of the original table structure
UPDATE Statement (2) UPDATE <myTable> {join} SET <Field1> = <Value1> WHERE {condition};
UPDATE Statement (2) UPDATE <myTable> {join} SET <Field1> = <Value1> WHERE {condition}; UPDATE PAT INNER JOIN TEMP ON PAT.PAT_ID = TEMP.PAT_ID SET PAT.PAT_TITLE = TEMP.TITLE ;
Updating Multiple Records(2) The medical procedure cost table needs to be reflect a 12.5% increase
UPDATE Statement (3) UPDATE <myTable> SET <Field1> = <Value1> WHERE {condition};
UPDATE Statement (3) UPDATE <myTable> SET <Field1> = <Value1> WHERE {condition}; UPDATE MED_PROCEDURE SET COST = 1.125 * COST ;
Deleting a Record DELETE FROM <myTable> {condition};
Deleting a Record DELETE FROM PAT WHERE PAT_ID = 983883; DELETE FROM <myTable> {condition};
Reading the Data: the SELECT Statement SELECT {fields || *} FROM <myTable>{condition};
Reading the Data: the SELECT Statement SELECT {fields || *} FROM <myTable>{condition}; SELECT PAT_LNM FROM PAT; SELECT * FROM PAT; SELECT MED_PROC_NM FROM MED_PROCEDURE WHERE COST > 20000;
Joins Who is the primary physician for patient Mary Lindfors?
Natural Join Who is/are the primary physician(s) for patient Mary Lindfors? SELECT PAT_FNM, PAT_LNM, CLNCIAN_NM FROM PAT, CLNCIAN WHERE PAT.PAT_ID = CLNCIAN.PAT_ID AND PAT_FNM = 'MARY' AND PAT_LNM = 'LINDFORS';
Outer Joins: RIGHT JOIN SELECT PAT.PAT_FNM, PAT.PAT_LNM, CLNCIAN.CLNCIAN_NM FROM CLNCIAN RIGHT JOIN PAT ON CLNCIAN.PAT_ID = PAT.PAT_ID; Shows all the records from PAT and those records from CLNCIAN where the PAT_ID values are equal in both tables
LEFT JOIN SELECT PAT.PAT_FNM, PAT.PAT_LNM, CLNCIAN.CLNCIAN_NM FROM CLNCIAN LEFT JOIN PAT ON CLNCIAN.PAT_ID = PAT.PAT_ID; Shows all the records from CLNCIAN and those records from PAT where the PAT_ID values are equal in both tables
Union Operator • The tables must have the same number of columns • Corresponding columns must all have identical data types and lengths • Command syntax Select * From <First Table name> Union Select * From <Second Table name>;
Union of Two Tables Recalled Medication in Use
Union of Two Tables Recalled Medication in Use
Union of Two Tables Recalled Medication in Use
Intersect • Only rows of data that appear in both source tables are selected • Command Syntax Select * From <Table name> Intersect Corresponding (<Fieldname>, <Fieldname>, …) Select * From <Second Table name>;
Except • Return all rows that appear in first table but not in the second table Select * From <Table name> Except Corresponding (<Fieldname>, <Fieldname>, …) Select * From <Second Table name>;
Take Home Lessons It is possible to write your own SQL for data manipulation