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databaseImportOptions

Define import options for database data

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Syntax

opts = databaseImportOptions(conn,source)
opts = databaseImportOptions(conn,source,Name,Value)

Description

opts = databaseImportOptions(conn,source) creates an SQLImportOptions object using the database connection and a source, which is a database table name or SQL query.

example

opts = databaseImportOptions(conn,source,Name,Value) specifies additional options using one or more name-value pair arguments. For example, 'Catalog',"toystore_doc" retrieves data from the toystore_doc database catalog.

example

Examples

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Open Live Script

Customize import options when importing data from a database table. Control the import options by creating an SQLImportOptions object. Then, customize import options for different database columns. Import data using the sqlread function.

This example uses the patients.xls file, which contains the columns Gender, Location, SelfAssessedHealthStatus, and Smoker. The example also uses a Microsoft® SQL Server® Version 11.00.2100 database and the Microsoft SQL Server Driver 11.00.5058.

Create a database connection to a Microsoft SQL Server database with Windows® authentication. Specify a blank username and password.

datasource = 'MS SQL Server Auth';
conn = database(datasource,'','');

Load patient information into the MATLAB® workspace.

patients = readtable('patients.xls');

Create the patients database table using the patient information.

tablename = 'patients';
sqlwrite(conn,tablename,patients)

Create an SQLImportOptions object using the patients database table and the databaseImportOptions function.

opts = databaseImportOptions(conn,tablename)
opts = 
  SQLImportOptions with properties:

           ExcludeDuplicates: false
          VariableNamingRule: 'modify'

               VariableNames: {'LastName', 'Gender', 'Age' ... and 7 more}
               VariableTypes: {'char', 'char', 'double' ... and 7 more}
       SelectedVariableNames: {'LastName', 'Gender', 'Age' ... and 7 more}
                  FillValues: {'', '',  NaN  ... and 7 more }
                   RowFilter: <unconstrained> 

             VariableOptions: Show all 10 VariableOptions

Display the current import options for the variables selected in the SelectedVariableNames property of the SQLImportOptions object.

vars = opts.SelectedVariableNames;
varOpts = getoptions(opts,vars)
varOpts = 
    1x10 SQLVariableImportOptions array with properties:

   Variable Options:
                      (1) |      (2) |      (3) |        (4) |      (5) |      (6) |      (7) |        (8) |         (9) |                       (10)
         Name: 'LastName' | 'Gender' |    'Age' | 'Location' | 'Height' | 'Weight' | 'Smoker' | 'Systolic' | 'Diastolic' | 'SelfAssessedHealthStatus'
         Type:     'char' |   'char' | 'double' |     'char' | 'double' | 'double' | 'double' |   'double' |    'double' |                     'char'
  MissingRule:     'fill' |   'fill' |   'fill' |     'fill' |   'fill' |   'fill' |   'fill' |     'fill' |      'fill' |                     'fill'
    FillValue:         '' |       '' |      NaN |         '' |      NaN |      NaN |      NaN |        NaN |         NaN |                         ''

	To access sub-properties of each variable, use getoptions

Change the data types for the Gender, Location, SelfAssessedHealthStatus, and Smoker variables using the setoptions function. Because the Gender, Location, and SelfAssessedHealthStatus variables indicate a finite set of repeating values, change their data type to categorical. Because the Smoker variable stores the values 0 and 1, change its data type to logical. Then, display the updated import options.

opts = setoptions(opts,{'Gender','Location','SelfAssessedHealthStatus'}, ...
    'Type','categorical');
opts = setoptions(opts,'Smoker','Type','logical');

varOpts = getoptions(opts,{'Gender','Location','Smoker', ...
    'SelfAssessedHealthStatus'})
varOpts = 
    1x4 SQLVariableImportOptions array with properties:

   Variable Options:
                         (1) |           (2) |       (3) |                        (4)
         Name:      'Gender' |    'Location' |  'Smoker' | 'SelfAssessedHealthStatus'
         Type: 'categorical' | 'categorical' | 'logical' |              'categorical'
  MissingRule:        'fill' |        'fill' |    'fill' |                     'fill'
    FillValue:   <undefined> |   <undefined> |         0 |                <undefined>

	To access sub-properties of each variable, use getoptions

Import the patients database table using the sqlread function, and display the last eight rows of the table.

data = sqlread(conn,tablename,opts);
tail(data)
      LastName       Gender    Age            Location             Height    Weight    Smoker    Systolic    Diastolic    SelfAssessedHealthStatus
    _____________    ______    ___    _________________________    ______    ______    ______    ________    _________    ________________________

    {'Foster'   }    Female    30     St. Mary's Medical Center      70       124      false       130          91               Fair             
    {'Gonzales' }    Male      48     County General Hospital        71       174      false       123          79               Good             
    {'Bryant'   }    Female    48     County General Hospital        66       134      false       129          73               Excellent        
    {'Alexander'}    Male      25     County General Hospital        69       171      true        128          99               Good             
    {'Russell'  }    Male      44     VA Hospital                    69       188      true        124          92               Good             
    {'Griffin'  }    Male      49     County General Hospital        70       186      false       119          74               Fair             
    {'Diaz'     }    Male      45     County General Hospital        68       172      true        136          93               Good             
    {'Hayes'    }    Male      48     County General Hospital        66       177      false       114          86               Fair

Display a summary of the imported data. The sqlread function applies the import options to the variables in the imported data.

summary(data)
Variables:

    LastName: 100×1 cell array of character vectors

    Gender: 100×1 categorical

        Values:

            Female       53   
            Male         47   

    Age: 100×1 double

        Values:

            Min          25   
            Median       39   
            Max          50   

    Location: 100×1 categorical

        Values:

            County General Hospital         39   
            St. Mary s Medical Center       24   
            VA Hospital                     37   

    Height: 100×1 double

        Values:

            Min          60   
            Median       67   
            Max          72   

    Weight: 100×1 double

        Values:

            Min          111  
            Median     142.5  
            Max          202  

    Smoker: 100×1 logical

        Values:

            True        34   
            False       66   

    Systolic: 100×1 double

        Values:

            Min         109   
            Median      122   
            Max         138   

    Diastolic: 100×1 double

        Values:

            Min           68  
            Median      81.5  
            Max           99  

    SelfAssessedHealthStatus: 100×1 categorical

        Values:

            Excellent       34   
            Fair            15   
            Good            40   
            Poor            11

Now set the filter condition to import only data for patients older than 40 years and not taller than 68 inches.

opts.RowFilter = opts.RowFilter.Age > 40 & opts.RowFilter.Height <= 68
opts = 
  SQLImportOptions with properties:

           ExcludeDuplicates: false
          VariableNamingRule: 'modify'

               VariableNames: {'LastName', 'Gender', 'Age' ... and 7 more}
               VariableTypes: {'char', 'categorical', 'double' ... and 7 more}
       SelectedVariableNames: {'LastName', 'Gender', 'Age' ... and 7 more}
                  FillValues: {'',  <undefined>,  NaN  ... and 7 more }
                   RowFilter: Age > 40 & Height <= 68 

             VariableOptions: Show all 10 VariableOptions

Again, import the patients database table using the sqlread function, and display a summary of the imported data.

data = sqlread(conn,tablename,opts);
summary(data)
Variables:

    LastName: 24×1 cell array of character vectors

    Gender: 24×1 categorical

        Values:

            Female       17   
            Male          7   

    Age: 24×1 double

        Values:

            Min           41  
            Median      45.5  
            Max           50  

    Location: 24×1 categorical

        Values:

            County General Hospital         13   
            St. Mary s Medical Center        5   
            VA Hospital                      6   

    Height: 24×1 double

        Values:

            Min          62   
            Median       66   
            Max          68   

    Weight: 24×1 double

        Values:

            Min         119   
            Median      137   
            Max         194   

    Smoker: 24×1 logical

        Values:

            True         8   
            False       16   

    Systolic: 24×1 double

        Values:

            Min          114  
            Median     121.5  
            Max          138  

    Diastolic: 24×1 double

        Values:

            Min           68  
            Median      81.5  
            Max           96  

    SelfAssessedHealthStatus: 24×1 categorical

        Values:

            Excellent        7   
            Fair             3   
            Good            10   
            Poor             4

Delete the patients database table using the execute function.

sqlquery = ['DROP TABLE ' tablename];
execute(conn,sqlquery)

Close the database connection.

close(conn)
Open Live Script

Customize import options when importing data from the results of an SQL query on a database. Control the import options by creating an SQLImportOptions object. Then, customize import options for different columns in the SQL query. Import data using the fetch function.

This example uses the employees_database.mat file, which contains the columns first_name, hire_date, and DEPARTMENT_NAME. The example also uses a Microsoft® SQL Server® Version 11.00.2100 database and the Microsoft SQL Server Driver 11.00.5058.

Create a database connection to a Microsoft SQL Server database with Windows® authentication. Specify a blank username and password.

datasource = 'MS SQL Server Auth';
conn = database(datasource,'','');

Load employee information into the MATLAB® workspace.

employeedata = load('employees_database.mat');

Create the employees and departments database tables using the employee information.

emps = employeedata.employees;
depts = employeedata.departments;

sqlwrite(conn,'employees',emps)
sqlwrite(conn,'departments',depts)

Create an SQLImportOptions object using an SQL query and the databaseImportOptions function. This query retrieves all information for employees who are sales managers or programmers.

sqlquery = strcat("SELECT * from employees e join departments d ", ...
    "on (e.department_id = d.department_id) WHERE ", ...
    "(job_id = 'IT_PROG' or job_id = 'SA_MAN')");
opts = databaseImportOptions(conn,sqlquery)
opts = 
  SQLImportOptions with properties:

           ExcludeDuplicates: false
          VariableNamingRule: 'modify'

               VariableNames: {'employee_id', 'first_name', 'last_name' ... and 13 more}
               VariableTypes: {'double', 'char', 'char' ... and 13 more}
       SelectedVariableNames: {'employee_id', 'first_name', 'last_name' ... and 13 more}
                  FillValues: { NaN, '', ''  ... and 13 more }
                   RowFilter: <unconstrained> 

             VariableOptions: Show all 16 VariableOptions

Display the current import options for the variables selected in the SelectedVariableNames property of the SQLImportOptions object.

vars = opts.SelectedVariableNames;
varOpts = getoptions(opts,vars)
varOpts = 
    1x16 SQLVariableImportOptions array with properties:

   Variable Options:
                         (1) |          (2) |         (3) |     (4) |            (5) |         (6) |      (7) |      (8) |              (9) |         (10) |            (11) |        (12) |            (13) |              (14) |         (15) |          (16)
         Name: 'employee_id' | 'first_name' | 'last_name' | 'email' | 'phone_number' | 'hire_date' | 'job_id' | 'salary' | 'commission_pct' | 'manager_id' | 'department_id' | 'temporary' | 'DEPARTMENT_ID' | 'DEPARTMENT_NAME' | 'MANAGER_ID' | 'LOCATION_ID'
         Type:      'double' |       'char' |      'char' |  'char' |         'char' |      'char' |   'char' | 'double' |         'double' |     'double' |        'double' |    'double' |        'double' |            'char' |     'double' |      'double'
  MissingRule:        'fill' |       'fill' |      'fill' |  'fill' |         'fill' |      'fill' |   'fill' |   'fill' |           'fill' |       'fill' |          'fill' |      'fill' |          'fill' |            'fill' |       'fill' |        'fill'
    FillValue:           NaN |           '' |          '' |      '' |             '' |          '' |       '' |      NaN |              NaN |          NaN |             NaN |         NaN |             NaN |                '' |          NaN |           NaN

	To access sub-properties of each variable, use getoptions

Change the data types for the hire_date, DEPARTMENT_NAME, and first_name variables using the setoptions function. Then, display the updated import options. Because hire_date stores date and time data, change the data type of this variable to datetime. Because DEPARTMENT_NAME designates a finite set of repeating values, change the data type of this variable to categorical. Also, change the name of this variable to lowercase. Because first_name stores text data, change the data type of this variable to string.

opts = setoptions(opts,'hire_date','Type','datetime');
opts = setoptions(opts,'DEPARTMENT_NAME','Name','department_name', ...
    'Type','categorical');
opts = setoptions(opts,'first_name','Type','string');

vars = opts.SelectedVariableNames;
varOpts = getoptions(opts,vars)
varOpts = 
    1x16 SQLVariableImportOptions array with properties:

   Variable Options:
                         (1) |          (2) |         (3) |     (4) |            (5) |         (6) |      (7) |      (8) |              (9) |         (10) |            (11) |        (12) |            (13) |              (14) |         (15) |          (16)
         Name: 'employee_id' | 'first_name' | 'last_name' | 'email' | 'phone_number' | 'hire_date' | 'job_id' | 'salary' | 'commission_pct' | 'manager_id' | 'department_id' | 'temporary' | 'DEPARTMENT_ID' | 'department_name' | 'MANAGER_ID' | 'LOCATION_ID'
         Type:      'double' |     'string' |      'char' |  'char' |         'char' |  'datetime' |   'char' | 'double' |         'double' |     'double' |        'double' |    'double' |        'double' |     'categorical' |     'double' |      'double'
  MissingRule:        'fill' |       'fill' |      'fill' |  'fill' |         'fill' |      'fill' |   'fill' |   'fill' |           'fill' |       'fill' |          'fill' |      'fill' |          'fill' |            'fill' |       'fill' |        'fill'
    FillValue:           NaN |    <missing> |          '' |      '' |             '' |         NaT |       '' |      NaN |              NaN |          NaN |             NaN |         NaN |             NaN |       <undefined> |          NaN |           NaN

	To access sub-properties of each variable, use getoptions

Select the three modified variables using the SelectVariableNames property.

opts.SelectedVariableNames = ["first_name","hire_date","department_name"];

Set the filter condition to import only the data for the employees hired before January 1, 2006.

opts.RowFilter = opts.RowFilter.hire_date < datetime(2006,01,01)
opts = 
  SQLImportOptions with properties:

           ExcludeDuplicates: false
          VariableNamingRule: 'modify'

               VariableNames: {'employee_id', 'first_name', 'last_name' ... and 13 more}
               VariableTypes: {'double', 'string', 'char' ... and 13 more}
       SelectedVariableNames: {'first_name', 'hire_date', 'department_name'}
                  FillValues: { NaN,  <missing>, ''  ... and 13 more }
                   RowFilter: hire_date < 01-Jan-2006 

             VariableOptions: Show all 16 VariableOptions

Import and display the results of the SQL query using the fetch function.

employees_data = fetch(conn,sqlquery,opts)
employees_data=4×3 table
    first_name     hire_date     department_name
    __________    ___________    _______________

    "David"       25-Jun-2005         IT        
    "John"        01-Oct-2004         Sales     
    "Karen"       05-Jan-2005         Sales     
    "Alberto"     10-Mar-2005         Sales

Delete the employees and departments database tables using the execute function.

execute(conn,'DROP TABLE employees')
execute(conn,'DROP TABLE departments')

Close the database connection.

close(conn)
Open Live Script

Customize import options when importing data from a database table. Control the import options by creating an SQLImportOptions object. Specify the location of the database table by using the database catalog and schema. Then, customize import options for different database columns. Import data using the sqlread function.

This example uses the patients.xls file, which contains the columns Gender, Location, SelfAssessedHealthStatus, and Smoker. The example also uses a Microsoft® SQL Server® Version 11.00.2100 database and the Microsoft SQL Server Driver 11.00.5058.

Create a database connection to a Microsoft SQL Server database with Windows® authentication. Specify a blank user name and password.

datasource = 'MS SQL Server Auth';
conn = database(datasource,'','');

Load patient information into the MATLAB® workspace.

patients = readtable('patients.xls');

Create the patients database table in the toy_store database catalog and dbo database schema using the patient information.

tablename = 'patients';
sqlwrite(conn,tablename,patients, ...
    'Catalog','toy_store','Schema','dbo')

Create an SQLImportOptions object using the patients database table and the databaseImportOptions function. Specify the toy_store database catalog and dbo database schema for the location of the database table.

opts = databaseImportOptions(conn,tablename, ...
    'Catalog','toy_store','Schema','dbo');

Display the current import options for the variables selected in the SelectedVariableNames property of the SQLImportOptions object.

vars = opts.SelectedVariableNames;
varOpts = getoptions(opts,vars)
varOpts = 
    1x10 SQLVariableImportOptions array with properties:

   Variable Options:
                      (1) |      (2) |      (3) |        (4) |      (5) |      (6) |      (7) |        (8) |         (9) |                       (10)
         Name: 'LastName' | 'Gender' |    'Age' | 'Location' | 'Height' | 'Weight' | 'Smoker' | 'Systolic' | 'Diastolic' | 'SelfAssessedHealthStatus'
         Type:     'char' |   'char' | 'double' |     'char' | 'double' | 'double' | 'double' |   'double' |    'double' |                     'char'
  MissingRule:     'fill' |   'fill' |   'fill' |     'fill' |   'fill' |   'fill' |   'fill' |     'fill' |      'fill' |                     'fill'
    FillValue:         '' |       '' |      NaN |         '' |      NaN |      NaN |      NaN |        NaN |         NaN |                         ''

	To access sub-properties of each variable, use getoptions

Change the data types for the Gender, Location, SelfAssessedHealthStatus, and Smoker variables using the setoptions function. Because the Gender, Location, and SelfAssessedHealthStatus variables indicate a finite set of repeating values, change their data type to categorical. Because the Smoker variable stores the values 0 and 1, change its data type to logical. Then, display the updated import options.

opts = setoptions(opts,{'Gender','Location','SelfAssessedHealthStatus'}, ...
    'Type','categorical');
opts = setoptions(opts,'Smoker','Type','logical');

varOpts = getoptions(opts,{'Gender','Location','Smoker', ...
    'SelfAssessedHealthStatus'})
varOpts = 
    1x4 SQLVariableImportOptions array with properties:

   Variable Options:
                         (1) |           (2) |       (3) |                        (4)
         Name:      'Gender' |    'Location' |  'Smoker' | 'SelfAssessedHealthStatus'
         Type: 'categorical' | 'categorical' | 'logical' |              'categorical'
  MissingRule:        'fill' |        'fill' |    'fill' |                     'fill'
    FillValue:   <undefined> |   <undefined> |         0 |                <undefined>

	To access sub-properties of each variable, use getoptions

Import the patients database table using the sqlread function, and display the last eight rows of the table. 

data = sqlread(conn,tablename,opts,'Catalog','toy_store','Schema','dbo');
tail(data)
ans=8×10 table
      LastName       Gender    Age            Location             Height    Weight    Smoker    Systolic    Diastolic    SelfAssessedHealthStatus
    _____________    ______    ___    _________________________    ______    ______    ______    ________    _________    ________________________

    {'Foster'   }    Female    30     St. Mary's Medical Center      70       124      false       130          91               Fair             
    {'Gonzales' }    Male      48     County General Hospital        71       174      false       123          79               Good             
    {'Bryant'   }    Female    48     County General Hospital        66       134      false       129          73               Excellent        
    {'Alexander'}    Male      25     County General Hospital        69       171      true        128          99               Good             
    {'Russell'  }    Male      44     VA Hospital                    69       188      true        124          92               Good             
    {'Griffin'  }    Male      49     County General Hospital        70       186      false       119          74               Fair             
    {'Diaz'     }    Male      45     County General Hospital        68       172      true        136          93               Good             
    {'Hayes'    }    Male      48     County General Hospital        66       177      false       114          86               Fair

Display a summary of the imported data. The sqlread function applies the import options to the variables in the imported data.

summary(data)
Variables:

    LastName: 100×1 cell array of character vectors

    Gender: 100×1 categorical

        Values:

            Female       53   
            Male         47   

    Age: 100×1 double

        Values:

            Min          25   
            Median       39   
            Max          50   

    Location: 100×1 categorical

        Values:

            County General Hospital         39   
            St. Mary s Medical Center       24   
            VA Hospital                     37   

    Height: 100×1 double

        Values:

            Min          60   
            Median       67   
            Max          72   

    Weight: 100×1 double

        Values:

            Min          111  
            Median     142.5  
            Max          202  

    Smoker: 100×1 logical

        Values:

            True        34   
            False       66   

    Systolic: 100×1 double

        Values:

            Min         109   
            Median      122   
            Max         138   

    Diastolic: 100×1 double

        Values:

            Min           68  
            Median      81.5  
            Max           99  

    SelfAssessedHealthStatus: 100×1 categorical

        Values:

            Excellent       34   
            Fair            15   
            Good            40   
            Poor            11

Delete the patients database table from the toy_store database catalog and the dbo database schema by using the execute function.

sqlquery = ['DROP TABLE toy_store.dbo.' tablename];
execute(conn,sqlquery)

Close the database connection.

close(conn)

Input Arguments

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Database connection, specified as a connection object created with the database function, connection object created with the mysql function, connection object created with the postgresql function, or sqlite object.

Create a parallelizable databaseDatastore object by first creating a parallel pool constant. You can use the getSecret function to retrieve your user credentials when you create this constant.

Example: conn = parallel.pool.Constant(@()postgresql(getSecret("PostgreSQL.username"),getSecret("Postgresql.password"),"Server","localhost","DatabaseName","toy_store"),@close);

Source, specified as a character vector or string scalar. Use the source input argument to specify the name of a database table or an SQL query for importing data from a database.

Example: "inventorytable"

Example: "SELECT * FROM inventorytable"

Data Types: char | string

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: opts = databaseImportOptions(conn,"inventorytable",'Catalog',"toystore_doc",'Schema',"dbo") defines import options for importing data from the inventorytable database table located in the toystore_doc catalog and dbo schema.

Database catalog name, specified as the comma-separated pair consisting of 'Catalog' and a character vector or string scalar. A catalog serves as the container for the schemas in a database and contains related metadata information. A database can have numerous catalogs.

Use the 'Catalog' name-value pair argument only when source is a database table.

Example: 'Catalog','toy_store'

Data Types: char | string

Database schema name, specified as the comma-separated pair consisting of 'Schema' and a character vector or string scalar. A schema defines the database tables, views, relationships among tables, and other elements. A database catalog can have numerous schemas.

Use the 'Schema' name-value pair argument only when source is a database table.

Example: 'Schema','dbo'

Data Types: char | string

Output Arguments

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Database import options, returned as an SQLImportOptions object.

Version History

Introduced in R2018b

See Also

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