Searching and Displaying Data

Lasso provides several parameters for the inline method for retrieving records within Lasso-compatible databases. These parameters are used in conjunction with name/value pair parameters in order to perform the desired database action in a specific database and table or within a specific record.

The inline action parameters documented in this chapter are listed below. The sections that follow describe the additional keyword and pair parameters required for each database action.

-search
Searches for records within a database.
-findAll
Finds all records within a database.
-random
Returns a random record from a database. (Only works with FileMaker Server databases.)

How Searches are Performed

The following describes each step that takes place every time a search is performed using Lasso:

  1. Lasso checks the database, table, and field name specified in the search to verify that they are all valid.
  2. The search query is formatted and sent to the database application. FileMaker Server search queries are formatted as URLs and submitted to the Web Publishing Engine. MySQL search queries are formatted as SQL statements and submitted directly to MySQL.
  3. The database application performs the desired search and assembles a found set. The database application is responsible for interpreting search criteria, wild cards in search strings, field operators, and logical operators.
  4. The database application sorts the found set based on sort criteria included in the search query. The database application is responsible for determining the order of records returned to Lasso.
  5. A subset of the found set is sent to Lasso as the result set. Only the number of records specified by -maxRecords starting at the offset specified by -skipRecords is returned to Lasso. If any -returnField parameters are included in a search then only those fields they specify are returned to Lasso.
  6. The result set can be displayed and manipulated using methods that return information about the result set and methods that return fields or other values.

Character Encoding

Lasso stores and retrieves data from data sources based on the preferences established in the “Datasources” section of Lasso Server Admin. The following rules apply for each standard data source:

Inline Host:The character encoding can be specified explicitly using a -tableEncoding parameter within the -host array.
Inline Table:The character encoding of the table specified using the -table parameter is used if -tableEncoding is not specified within the -host array.
MySQL:By default all communication is encoded as UTF-8.
FileMaker Server:
 By default all communication is in the MacRoman character set when Lasso Server is hosted on OS X, or in the Latin-1 (ISO-8859-1) character set when Lasso Server is hosted on Windows.
ODBC:Encoding of communication with ODBC data sources is dependent on the encoding of the table being accessed.

Error Reporting

After a database action has been performed, Lasso reports any errors that occurred via the error_currentError method. The value of this method should be checked to verify that the database action was successfully performed.

Display Current Error Code and Message

The following code can be used to display the current error message. This code should be placed in a Lasso page that is a response to a database action or within the capture block of an inline method.

error_code + ': ' + error_msg

If the database action was performed successfully then the following result will be returned:

// => 0: No Error

Check for a Specific Error Code and Message

The following example shows how to report a specific error if one occurs using a conditional if statement to check if the current error message is equal to error_databaseTimeout:

if(error_currentError == error_databaseTimeout)
   'Connection to database lost!'
/if

Full documentation about error methods and error codes can be found in the Error Handling chapter.

Searching Records

Searches can be performed within any Lasso-compatible database using the -search parameter in an inline method. The -search parameter requires that a number of additional parameters be defined in order to perform the search. The additional required parameters are detailed in the table -Search Action Requirements along with a description of other recommended or optional parameters specific to the -search action.

Additional optional parameters are described in the tables Search Operator Parameters and Result Parameters in the sections that follow.

-Search Action Requirements
Parameter Description
-search The action that is to be performed. Required.
-database=? The database that should be searched. Required.
-table=? The table from the specified database that should be searched. Required.
-keyField=? The name of the field that holds the primary key for the specified table. Recommended.
-keyValue=? The particular value for the primary key of the record that should be returned. Using -keyValue overrides all the other search parameters and returns the single record specified. Optional.
-key=? An array that specifies the search field operators and pair parameters to find the matching records. Using -key overrides any other specified name/value pairs.
-host=? Optional inline host array. See the section Inline Connection Options in the Database Interaction Fundamentals chapter for more information.
name/value pairs A variable number of name/value pair parameters specify the query that will be performed. Any pair parameters included in the search action will be used to define the query that is performed in the specified table. All pair parameters must reference a field within the database. Any fields that are not referenced will be ignored for the purposes of the search.

Search a Database Using an Inline

The following example shows how to search a database by specifying the required parameters within an inline method. The -database is set to “contacts”, -table is set to “people”, and -keyField is set to “id”. The search returns records that contain “John” with the field “first_name”.

The results of the search are displayed to the visitor inside the inline. The records method will repeat for each record in the found set. The field methods will display the value for the specified field from the current record being shown.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'='John'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

If the search was successful then the following results will be returned:

// =>
// <br />John Person
// <br />John Doe

Additional pair parameters and keyword parameters can be used to generate more complex searches. These techniques are documented in the section Search Operators later in this chapter.

Search a Database Using Visitor-Supplied Values

The following example shows how to search a database by specifying the required parameters within an inline method, but allowing a site visitor to specify the search criteria in an HTML form. The visitor is presented with an HTML form in the Lasso page “default.lasso”. The HTML form contains two text inputs for “first_name” and “last_name” and a submit button. The action of the form is the response page “response.lasso” which contains the inline that will perform the search. The contents of the “default.lasso” file include the following:

<form action="response.lasso" method="POST">
   <br />First Name: <input type="text" name="first_name" value="" />
   <br />Last Name: <input type="text" name="last_name" value="" />
   <br /><input type="submit" name="submit" value="Search" />
</form>

The search is performed and the results of the search are displayed to the visitor inside the inline method in “response.lasso”. The values entered by the visitor in the HTML form in “default.lasso” are inserted into the inline using the web_request->param method. The records method will execute the capture block for each record in the found set. The field methods will display the value for the specified field from the current record being shown. The contents of the “response.lasso” file include the following:

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'=web_request->param('first_name'),
   'last_name'=web_request->param('last_name')
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

If the visitor entered “John” for “first_name” and “Person” for “last_name” then the following result would be returned:

// =>
// <br />John Person

Search Operators

Lasso inlines include a set of parameters that allow operators to be used to create complex database queries. These parameters are summarized in the table Search Operator Parameters.

Search Operator Parameters
Parameter Description
-operatorLogical=? or -opLogical=? Specifies the logical operator for the search. Abbreviated as -opLogical. Defaults to AND.
-operator=? or -op=? When specified before a pair parameter, sets the search operator for that parameter. Abbreviated as -op. Defaults to “bw”. See below for a full list of field operators, which can also be written as -bw, -ew, -cn, etc.
-operatorBegin=? or -opBegin=? Specifies the logical operator for all search parameters until -operatorEnd is reached. Abbreviated as -opBegin.
-operatorEnd=? or -opEnd=? Specifies the end of a logical operator grouping started with -operatorBegin. Abbreviated as -opEnd.

The operator parameters are divided into two categories:

Field Operators
These are specified using the -operator parameter before a name/value pair parameter. The field operator changes the way that the named field is searched for the value. If no field operator is specified then the default begins with operator (“bw”) is used. See the table Search Field Operators for a list of the possible values. Field operators can also be abbreviated as -bw, -ew, -cn, etc.
Logical Operators
These are specified using the -operatorLogical, -operatorBegin, and -operatorEnd parameters. These parameters specify how the results of different pair parameters are combined to form the full results of the search. You cannot mix -operatorLogical with -operatorBegin and -operatorEnd.

Field Operators

The possible values for the -operator parameter are listed in the table Search Field Operators. The default operator is begins with (“bw”). Case is not considered when specifying operators. Several of the field operators are only supported in MySQL or other SQL databases. These include the “ft” full-text operator and the “rx” and “nrx” regular expression operators, which are described further in the table MySQL Additional Search Field Operators.

Search Field Operators
Operator Description
-op='bw' or -bw Begins With. Default if no operator is set.
-op='nbw' or -nbw Not Begins With.
-op='cn' or -cn Contains.
-op='ncn' or -ncn Not Contains.
-op='eq' or -eq Equals.
-op='neq' or -neq Not Equals.
-op='ew' or -ew Ends With.
-op='new' or -new Not Ends With.
-op='gt' or -gt Greater Than.
-op='gte' or -gte Greater Than or Equals.
-op='lt' or -lt Less Than.
-op='lte' or -lte Less Than or Equals.
-op='ft' or -ft Full-Text Search. MySQL databases only.
-op='rx' or -rx Regular Expression Search. MySQL databases only.
-op='nrx' or -nrx Not Regular Expression Search. MySQL databases only.

Field operators are interpreted differently depending on which data source is being accessed. For example, FileMaker Server interprets “bw” to mean that any word within a field can begin with the value specified for that field. MySQL interprets “bw” to mean that the first word within the field must begin with the value specified. See the chapters on each data source or the documentation that came with a third-party data source connector for more information.

Specify a Field Operator in an Inline

Specify the field operator before the name/value pair parameter that it will affect. The following inline method searches for records where the “first_name” begins with “J” and the “last_name” ends with “son”:

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -operator='bw', 'first_name'='J',
   -operator='ew', 'last_name'='son'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name')
   ^}
^}

The same could be accomplished by using a -key parameter:

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -key=(: -bw, 'first_name'='J', -ew, 'last_name'='son')
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

The results of the search would include the following records:

// =>
// <br />John Person
// <br />Jane Person

Logical Operators

The logical operator parameter -operatorLogical can be used with a value of either “And” or “Or”. The parameters -operatorBegin and -operatorEnd can be used with values of “And”, “Or”, or “Not”. An -operatorLogical applies to all search parameters specified with an action while -operatorBegin applies to all search parameters until the matching -operatorEnd parameter is reached. (Thus the two cannot be mixed into the same inline.) The case of the value is unimportant when specifying a logical operator.

  • AND – Specifies that records that are returned should fulfill all of the search parameters listed.
  • OR – Specifies that records that are returned should fulfill one or more of the search parameters listed.
  • NOT – Specifies that records that match the search criteria contained between the -operatorBegin and -operatorEnd parameters should be omitted from the found set. The NOT operator cannot be used with the -operatorLogical keyword parameter.

Tip

In lieu of a NOT option for -operatorLogical, many field operators can be negated individually by substituting the opposite field operator. The following pairs of field operators are the opposites of each other: “eq” and “neq”, “lt” and “gte”, and “gt” and “lte”.

Note

The -operatorBegin and -operatorEnd parameters do not work with Lasso Connector for FileMaker Server.

Perform a Search Using an AND Operator

Use the -operatorLogical command tag with an “And” value. The following inline method returns records for which the “first_name” field begins with “John” and the “last_name” field begins with “Doe”. The position of the -operatorLogical parameter within the inline is unimportant since it applies to the entire action.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -operatorLogical='And',
   'first_name'='John',
   'last_name'='Doe'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name')
   ^}
^}

// => <br />John Doe

Perform a Search Using an OR Operator

Use the -operatorLogical parameter with an “Or” value. The following inline method returns records for which the “first_name” field begins with either “John” or “Jane”. The position of the -operatorLogical parameter within the inline is unimportant since it applies to the entire action.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -operatorLogical='Or',
   'first_name'='John',
   'first_name'='Jane'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

// =>
// <br />John Doe
// <br />Jane Doe
// <br />John Person

Perform a Search Using a NOT Operator

Use the -operatorBegin and -operatorEnd parameters with a “Not” value. The following inline method returns records for which the “first_name” field begins with “John” and the “last_name” field is not “Doe”. The operator parameters must surround the parameters of the search that is to be negated.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'='John',
   -operatorBegin='Not',
      'last_name'='Doe',
   -operatorEnd='Not'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name')
   ^}
^}

// => <br />John Person

Perform a Search with a Complex Query

Use the -operatorBegin and -operatorEnd parameters to build up a complex query. As an example, a query can be constructed to find records in a database whose “first_name” and “last_name” both begin with the same letter “J” or “M”. The desired query could be written in pseudocode as follows:

( (first_name begins with J) AND (last_name begins with J) )
OR
( (first_name begins with M) AND (last_name begins with M) )

To translate this into an inline statement, each line of the query becomes a pair of -opBegin='And' and -opEnd='And' parameters with a pair parameter for “first_name” and “last_name” contained inside. The two lines are then combined using a pair of -opBegin='Or' and -opEnd='Or' parameters. The nesting of the parameters works like the nesting of parentheses in the pseudocode above to clarify how Lasso should combine the results of different name/value pair parameters.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -opBegin='Or',
      -opBegin='And',
         'first_name'='J',
         'last_name'='J',
      -opEnd='And',
      -opBegin='And',
         'first_name'='M',
         'last_name'='M',
      -opEnd='And',
   -opEnd='Or'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

The returned result might look something like this:

// =>
// <br />Johnny Johnson
// <br />Jimmy James
// <br />Mark McPerson

Returning Records

Lasso inlines include a set of parameters that allow the results of a search to be customized. These parameters do not change the found set of records that are returned from the search, but they do change the data that is returned for formatting and display to the visitor. The result parameters are summarized in the table Result Parameters.

See also

Result Parameters
Parameter Description
-sortField=? or -sortColumn=? Specifies that the results should be sorted based on the data in the named field. Multiple -sortField parameters can be used for complex sorts. Optional, defaults to returning data in the order it appears in the database.
-sortOrder=? When specified after a -sortField parameter, specifies the order of the sort, either “ascending”, “descending” or custom. Optional, defaults to “ascending” for each -sortField.
-maxRecords=? Specifies how many records should be shown from the found set. Optional, defaults to “50”.
-skipRecords=? Specifies an offset into the found set at which records should start being shown. Optional, defaults to “1”.
-returnField=? or -returnColumn=? Specifies a field that should be returned in the results of the search. Multiple -returnField parameters can be used to return multiple fields. Optional, defaults to returning all fields in the searched table.

The result parameters are divided into three categories:

  1. Sorting is specified using the -sortField and -sortOrder parameters. These parameters change the order of the records that the search returns. The database application performs the sort before Lasso receives the record set.

  2. The portion of the Found Set being shown is specified using the -maxRecords and -skipRecords parameters. -maxRecords sets the number of records that will be iterated over in the records method, while -skipRecords sets the offset into the found set that is shown. These two parameters define the window of records that are shown and can be used to navigate through a found set.

  3. The Fields that are available are specified using the -returnField parameter. Normally, all fields in the searched table are returned. If any -returnField parameters are specified then only those fields will be available for display using the field method. Specifying -returnField parameters can improve the performance of Lasso by not sending unnecessary data between the database and the web server.

    Note

    In order to use the keyField_value method within an inline, the -keyField must be specified as one of the -returnField values.

Return Sorted Results

Specify -sortField and -sortOrder parameters within an inline search. The following inline includes sort parameters. The records are first sorted by “last_name” in ascending order, then sorted by “first_name” in ascending order:

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'='J',
   -sortField='last_name',  -sortOrder='ascending',
   -sortField='first_name', -sortOrder='ascending'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

The following results could be returned when this inline is run. The returned records are sorted in order of “last_name”. If the “last_name” of two records are equal then those records are sorted in order of “first_name”.

// =>
// <br />Jane Doe
// <br />John Doe
// <br />Jane Person
// <br />John Person

Return a Portion of a Found Set

A portion of a found set can be returned by manipulating the values for -maxRecords and -skipRecords. In the following example, a search is performed for records where the “first_name” begins with “J”. This search returns four records, but only the second two records are shown. -maxRecords is set to “2” to show only two records and -skipRecords is set to “2” to skip the first two records.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'='J',
   -maxRecords=2,
   -skipRecords=2
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

The following results could be returned when this inline is run. Neither of the “Doe” records from the previous example are shown since they are skipped over.

// =>
// <br />Jane Person
// <br />John Person

Limit Fields Returned in Search Results

Use the -returnField parameter. If a single -returnField parameter is used then only the fields that are specified will be returned. If no -returnField parameters are specified then all fields within the current table will be returned. In the following example, only the “first_name” field is shown since it is the only field specified within a -returnField parameter:

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   'first_name'='J',
   -returnField='first_name'
) => {^
   records => {^
      '<br />' + field('first_name') + '\n'
   ^}
^}

The “last_name” field cannot be shown for any of these records since it was not specified in a``-returnField`` parameter. The above code would result in something like the following:

// =>
// <br />John
// <br />Jane
// <br />Jane
// <br />John

If the data source is MySQL, the -distinct parameter can be added to just return two records instead of four; one with the first name of “John” and the other with “Jane” See the SQL Data Sources chapter for details on the -distinct parameter.

Finding All Records

All records can be returned from a database using the -findAll parameter. The -findAll parameter functions exactly like the -search parameter except that no name/value pair parameters or operator parameters are required. Parameters that sort and limit the found set work the same as they do for -search actions.

-FindAll Action Requirements
Parameter Description
-findAll The action that is to be performed. Required.
-database=? The database that should be searched. Required.
-table=? The table from the specified database that should be searched. Required.
-keyField=? The name of the field that holds the primary key for the specified table. Recommended.
-host=? Optional inline host array. See the section Inline Connection Options in the Database Interaction Fundamentals chapter for more information.

Return All Records from a Database

The following inline method finds all records within a table named “people” in the “contacts” database and displays them. The results are shown below:

inline(
   -findAll,
   -database='contacts',
   -table='people',
   -keyField='id'
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name') + '\n'
   ^}
^}

// =>
// <br />John Doe
// <br />Jane Doe
// <br />John Person
// <br />Jane Person

Finding Random Records

A random record can be returned from a FileMaker database using the -random parameter. The -random parameter functions exactly like the -search parameter except that no name/value pair parameters or operator parameters are required.

-Random Action Requirements
Parameter Description
-random The action that is to be performed. Required.
-database=? The database that should be searched. Required.
-table=? The table from the specified database that should be searched. Required.
-keyField=? The name of the field that holds the primary key for the specified table. Recommended.
-host=? Optional inline host array. See the section Inline Connection Options in the Database Interaction Fundamentals chapter for more information.

Return a Random Record from a Database

The following inline finds a single random record from a FileMaker Server database “contacts” and displays it. The -maxRecords is set to “1” to ensure that only a single record is shown. One potential result is shown below. Each time this inline is run a different record will be returned.

inline(
   -random,
   -database='contacts',
   -table='people',
   -keyField='id',
   -maxRecords=1
) => {^
   records => {^
      '<br />' + field('first_name') + ' ' + field('last_name')
   ^}
^}

// => <br />Jane Person

Displaying Data

The examples in this chapter have all relied on the records method and field method to display the results of the search that have been performed. This section describes the use of these methods in more detail. (See the section Inline Action Result Methods in the Database Interaction Fundamentals chapter for method documentation and more information.)

The field method always returns the value for a field from the current record when it is used within a capture block of a records method. If the field method is used outside of records block but inside an inline capture block, then it returns the value for the field from the first record in the found set. If the found set has only one record then the records method is optional.

Note

For clarity, the example code in these chapters display data exactly as returned from the database, but production code should use encodeHtml, encodeXml, or an encoding parameter with field calls to ensure characters are proplerly formatted for the chosen output format.

Display Result for a Single Record

Use field methods within the capture block of an inline method. The records methods are unnecessary if only a single record is returned. The following inline performs a -search for a single record whose primary key ‘id’ equals “1”. The keyField_value is shown along with the field values for the record.

inline(
   -search,
   -database='contacts',
   -table='people',
   -keyField='id',
   -keyValue=1
) => {^
   '<br />' + keyField_value + ': ' + field('first_name') + ' ' + field('last_name') + '\n'
^}

// =>
// <br />1: Jane Doe

Display Results from a Named Inline

Use the -inlineName parameter in both the inline method and in the records method. The records method can be located anywhere in the code after the inline that define the database action. The following example shows a -findAll action at the top of a page of code with the results formatted later:

inline(
   -inlineName='FindAll Results',
   -findAll,
   -database='contacts',
   -table='people',
   -keyField='id'
) => {}

// ...

records(-inlineName='FindAll Results') => {^
   '<br />' + loop_count + ': ' + field('first_name') + ' ' + field('last_name') + '\n'
^}

// =>
// <br />1: John Doe
// <br />2: Jane Doe
// <br />3: John Person
// <br />4: Jane Person