Search expression n – This is the expressions with which the expression will be compared one by one. Search expression 1, Search expression 2, Search expression 3, …. If they evaluate to true, the return value is returned or else if default value is specified then it is returned else NULL is return if a comparison of the expression and the search expression evaluates false. Before comparing this value, it is converted into the datatype of the search expression 1. The terminologies used in the above syntax are as described here –Įxpression or value – This is the literal value of an expression or a column name of the table, which we have to compare with the search expressions. The above statement will fetch the data from T_My_XML_Table table.DECODE (expression/value, search expression 1, return value 1, …. Select extractValue(Value(ma),’/Project/Employee/Name)įrom T_My_XML_Table /*Assuming T_My_XML_Table has data of Employee*/,table(XMLSequence(extract(OBJECT_VALUE,’/project/company/employees’))) If you want to fetch the records in T_My_XML_Table then you require to use few functions like- extactValue and if you need specific data then you need to use some important filter conditions. You can also create the XMLTYPE table also, Step 1 : You can create separate column of XMLType in table level to store the XML type data. But Here i would like to give you some important examples for the same. This is also a big topic and i will create separate article for the same. createSchemaBasedXML(‘Put-your-schema-URL’) Įxample 4 : How to run select statement over XML It will give you better control on processing information. This step will improve the qualty of sending and receiving the XML files in the database. Checking the format of file is one of the important step while you dealing with xml files. The quality also matters when you are dealing with the XML file types. V_xmlSchema :=xmlType(‘Put your xsd schema definition here’) ĭbms_xmlschema.registerSchema( V_Schema_URL, V_xmlSchema ,FALSE) Įxample 3 : How to do Validation of XML to XSD in Oracle DB step 1 : Delete old schema before register new schemaĭBMS_leteSchema( V_Schema_URL =>’ABCD.xsd’, delete_option=>DBMS_XMLSchema.Delete_Cascade_Force) V_Schema_URL varchar2(500) := ‘ Put_your_schema_URL’ You need to use the XSD schema to verify the file is processed successfully and schema and contents of xml file are correct. There are so many inbound applications in real life scenarios and we require to validate that the correct XML file is coming from correct source. V_XMLType : xmlType( V_clob) -Use xmlType function to convert CLOB to xmlType. You can not use the XMLDB operators with using CLOB datatype and we have to convert the CLOB datatype to XMLtype. To process the data with using XMLDB package we must require to convert the datatype to XMLtype. The first example i would like to give this because in many real life applications we are using the CLOB datatypes. We might have seen some examples of converting the BLOB/CLOB datatypes in XMLtypes.Įxample 1 : How to convert CLOB to XMLtype? In our day to day scenarios we require to perform the multiple xml operations. We will see multiple examples of how to convert, how to select and how to check the data from xml files. In this section I would like to give you the multiple scenarios of processing the XML data with using Oracle PL/SQL through XMLDB package. How to process XML data with Oracle PL/SQL through XMLDB? I will not go in to deep and will prepare separate article for the XML Parsers. We require to run the xml parser and use its different interfaces of XML Parser to read the xml files. XML Parser Location : $ORACLE_HOME/xdk/plsql/parser The first step is to access the XML parser and run the xml parser. There are so many Java based application will generate the data in XML format and there is necessary to process the xml data and give it to other applications or keep it in human readable format. The XML Parsers are important PL/SQL parsers which we are using to process the XML files. How to process XML data with Oracle PL/SQL with multiple scenarios. The article will give information about how to do the xml file processing with multiple scenarios. Oracle has introduced a separate in built package for processing the xml data named XMLDB package. In this article i would like to give you information about the how to process XML data with Oracle PL/SQL with multiple real life examples. In my previous article I have given the examples of how to do performance tuning for PostgreSQL with examples.
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