Insert Items in NoSQL Tables

Catalyst enables you to insert items in a specific NoSQL table after you construct them. The items can be inserted in different ways as described in this section.

You can refer to the help sections on adding and working with data, the Catalyst custom JSON format, and the supported data types to learn these topics in detail.

Insert Items without Conditions

You can insert new items into a NoSQL table without any conditions by constructing the items in the Catalyst custom JSON format. This will require you to mandatorily pass the values for the partition key and sort key attributes configured for the table.

For example, in the code snippet below, the values for the partition key and sort key attributes of the item, fruitName and Location respectively, are provided. Other attributes of the string data type such as fruitType and availability are provided as a list fruitProperties. The item is then inserted using the insert_items() method.

    

        
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# Insert a NoSQL item without conditions
item = {
 
	 "fruitName": {
		 "S": "Banana"
 	},
	"Location": {
    "S": "Indonesia"
   },

	 "fruitProperties": {
 		"L": [
			{ 
			"fruitType": "Berries"
			},
 			{ 
    		"availability": "abundant"
  			 }
		}

		]
 	}
 }
 # Insert the item based on the defined condition and set the item to be returned in the response. Other supported values are "OLD" and "NULL"

 res = table.insert_items({ 
	 'item': item,
	'return': 'NEW' 
})
    

Insert Items with Conditional Functions

You can insert attributes in existing items in a NoSQL table using specific conditions that you define in the Catalyst custom JSON format. In this type, the existing data of the table is retrieved and evaluated against the specified condition. The items are inserted only if the evaluation is true. If there is no existing data, the conditions are ignored and the items are inserted.

Catalyst supports multiple operators to evaluate conditions. The supported operators are represented as shown below.

The example below illustrates this by defining a condition for the nested attribute fruitColour in the existing data to contain the value “Yellow”. This attribute is part of the attribute fruitProperties. If the condition is satisfied, the attributes fruitType and availability are added to the items. The item is then inserted using the insert_items() method.

    

        
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# Insert a NoSQL item with a conditional function
condition_function = {
 	"function": {
		"function_name": "attribute_type",
			"args": [ {
 				"attribute_path": ["fruitProperties", "[0]"]
 					}, 
					{
		"fruitColour": "Yellow"
			}
 		]
 	}
 }
 item = {
 	"Location": {
 		"S": "Indonesia"
 	},
	 "fruitName": {
		"S": "Banana"
 	},
	"fruitProperties": {
 		"L": [
			{ 
			"fruitType": "Berries"
			},
 			{ 
    "availability": "abundant"
    }
		}

		]
	}
 }
 # Insert the item based on the defined condition and set the return value in the response. Other supported values are "OLD" and "NULL"

 res = table.insert_items({ 
	'item': item,
	'condition': condition_function,
	'return': 'NEW' 
})
    

Insert Items with Conditional Operators

Catalyst also enables you to insert items based on conditions defined with operators in the Catalyst custom JSON format. The existing data of the table is retrieved and evaluated against the specified condition. The items are inserted only if the evaluation is true. If there is no existing data, the conditions are ignored and the items are inserted.

Catalyst supports multiple operators to evaluate conditions, as listed in the previous section.

The example below illustrates inserting an item based on conditions defined with the between operator. The condition states that only when the attribute count has values between 0 and 10 in the existing data, the attributes backupID and count are to be inserted in those items. The item is inserted with the insert_items() method.

    

        
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# Insert a NoSQL item with a conditional operator
condition_function = {
	"attribute": ["count"],
	"operator": "between",
	"value": {
	"L": [
		{ 
		"N": "0" 
		},
		{ 
		"N": "10"
		}
      	]
     }
    }

item = {
 	"countryCode": {
		"N": 054
			 },
		"backupID": {
			"N": 2379992
 			},
 	"count": {
      "N": "3"
     }
    }
# Insert the item based on the defined condition and set the return value in the response. Other supported values are "OLD" and "NULL"

res = table.insert_items({ 
'item': item,
'condition': condition_function,
'return': 'NEW' 
})