Help Center/ GaussDB(DWS)/ SQL Syntax Reference/ SQL Syntax Reference (8.1.3.x)/ Functions and Operators/ XML Functions/ Mapping a Table to XML
Updated on 2024-09-03 GMT+08:00
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Mapping a Table to XML

The functions in this section map the contents of the relational table to XML values. This is similar to exporting table in XML format.

Function parameters:

  • tbl: table name.
  • nulls: indicates whether the output contains null values. If the value is true, the null value in the column is <columnname xsi:nil="true"/>. If the value is false, the columns containing null values are omitted from the output.
  • tableforest: If this parameter is set to true, XML fragments are generated. If this parameter is set to false, XML files are generated.
  • targetns: specifies the XML namespace of the desired result. If this parameter is not specified, an empty string is passed.
  • query: SQL query statement
  • cursor: cursor name
  • count: amount of data obtained from the cursor
  • schema: schema name

table_to_xml(tbl regclass, nulls boolean, tableforest boolean, targetns text)

Description: Maps the contents of a table to XML values.

Return type: XML

If tableforest is false, the XML document in the result is similar to the following:

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<tablename>
  <row>
    <columnname1>data</columnname1>
    <columnname2>data</columnname2>
  </row>

  <row>
    ...
  </row>

  ...
</tablename>

If tableforest is true, the XML content in the result is similar to the following:

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<tablename>
  <columnname1>data</columnname1>
  <columnname2>data</columnname2>
</tablename>

<tablename>
  ...
</tablename>

...

table_to_xmlschema(tbl regclass, nulls boolean, tableforest boolean, targetns text)

Description: Maps a relational table schema to an XML schema document.

Return type: XML

The result of the schema content mapping is similar to the following:

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<schemaname>

table1-mapping

table2-mapping

...

</schemaname>

The format of the table mapping depends on the tableforest parameter.

table_to_xml_and_xmlschema(tbl regclass, nulls boolean, tableforest boolean, targetns text)

Description: Maps a relational table to XML values and schema documents.

Return type: XML

query_to_xml(query text, nulls boolean, tableforest boolean, targetns text)

Description: Maps the contents of an SQL query to XML values.

Return type: XML

query_to_xmlschema(query text, nulls boolean, tableforest boolean, targetns text)

Description: Maps an SQL query into an XML schema document.

Return type: XML

query_to_xml_and_xmlschema(query text, nulls boolean, tableforest boolean, targetns text)

Description: Maps SQL queries to XML values and schema documents.

Return type: XML

cursor_to_xml(cursor refcursor, count int, nulls boolean, tableforest boolean, targetns text)

Description: Maps a cursor query to an XML value.

Return type: XML

cursor_to_xmlschema(cursor refcursor, nulls boolean, tableforest boolean, targetns text)

Description: Maps a cursor query to an XML schema document.

Return type: XML

schema_to_xml(schema name, nulls boolean, tableforest boolean, targetns text)

Description: Maps a table in a schema to an XML value.

Return type: XML

schema_to_xmlschema(schema name, nulls boolean, tableforest boolean, targetns text)

Description: Maps a table in a schema to an XML schema document.

Return type: XML

schema_to_xml_and_xmlschema(schema name, nulls boolean, tableforest boolean, targetns text)

Description: Maps a table in a schema to an XML value and a schema document.

Return type: XML

database_to_xml(nulls boolean, tableforest boolean, targetns text)

Description: Maps a database table to an XML value.

Return type: XML

The result of the database content mapping may be similar to the following:

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<dbname>

<schema1name>
  ...
</schema1name>

<schema2name>
  ...
</schema2name>

...

</dbname>

database_to_xmlschema(nulls boolean, tableforest boolean, targetns text)

Description: Maps a database table to an XML schema document.

Return type: XML

database_to_xml_and_xmlschema(nulls boolean, tableforest boolean, targetns text)

Description: Maps database tables to XML values and schema documents.

Return type: XML

Parent topic: XML Functions