Package nzilbb.labbcat.server.db

Class GraphAgqlToSql

java.lang.Object

nzilbb.labbcat.server.db.GraphAgqlToSql

public class GraphAgqlToSql
extends Object

Converts AGQL expressions into SQL queries for matching graphs (transcripts).

Author:

Robert Fromont robert@fromont.net.nz

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GraphAgqlToSql.Query	Encapsulates the results of sqlFor(String,String,String,String,String) including the SQL.

Constructor Summary

Constructors

Constructor	Description
GraphAgqlToSql()	Default constructor.
GraphAgqlToSql(nzilbb.ag.Schema schema)	Attribute constructor.

Method Summary

Modifier and Type	Method	Description
nzilbb.ag.Schema	getSchema()	Getter for schema.
GraphAgqlToSql	setSchema(nzilbb.ag.Schema schema)	Setter for schema.
GraphAgqlToSql.Query	sqlFor(String expression, String sqlSelectClause, String userWhereClause, String orderClause, String sqlLimitClause)	Transforms the given AGQL query into an SQL query.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GraphAgqlToSql

public GraphAgqlToSql()

Default constructor.

GraphAgqlToSql

public GraphAgqlToSql(nzilbb.ag.Schema schema)

Attribute constructor.

Method Detail

getSchema

public nzilbb.ag.Schema getSchema()

Getter for schema.

Returns:

Layer schema.

setSchema

public GraphAgqlToSql setSchema(nzilbb.ag.Schema schema)

Setter for schema.

Parameters:

schema - Layer schema.

Returns:

this.

sqlFor

public GraphAgqlToSql.Query sqlFor(String expression,
                                   String sqlSelectClause,
                                   String userWhereClause,
                                   String orderClause,
                                   String sqlLimitClause)
                            throws nzilbb.ag.ql.AGQLException

Transforms the given AGQL query into an SQL query.

Parameters:

expression - The graph-matching expression, for example:

• id MATCHES 'Ada.+'
• 'Robert' IN labels('participant')
• first('corpus').label = 'CC'
• first('episode').label = 'Ada Aitcheson'
• first('transcript_scribe').label = 'Robert'
• first('participant_languages').label = 'en'
• first('noise').label = 'bell'
• 'en' IN labels('transcript_languages')
• 'en' IN labels('participant_languages')
• 'bell' IN labels('noise')
• all('transcript_languages').length gt; 1
• all('participant_languages').length gt; 1
• all('transcript').length gt; 100
• 'Robert' IN annotators('transcript_rating')
• id NOT MATCHES 'Ada.+' AND first('corpus').label = 'CC' AND 'Robert' IN labels('participant')

sqlSelectClause - The SQL expression that is to go between SELECT and FROM.

userWhereClause - The expression to add to the WHERE clause to ensure the user doesn't get access to data to which they're not entitled, or null.

orderClause - A comma-separated list of AGQL expressions to determine the order of results; e.g. "first('corpus').label, id", or null.

sqlLimitClause - The SQL LIMIT clause to append, or null for no LIMIT clause.

Throws:

nzilbb.ag.ql.AGQLException - If the expression is invalid.