Get & Scalar Query
This guide demonstrates how to get entities by ID and conduct scalar filtering. A scalar filtering retrieves entities that match the specified filtering conditions.
Overview
A scalar query filters entities in a collection based on a defined condition using boolean expressions. The query result is a set of entities that match the defined condition. Unlike a vector search, which identifies the closest vector to a given vector in a collection, queries filter entities based on specific criteria.
In Milvus, a filter is always a string compising field names joined by operators. In this guide, you will find various filter examples. To learn more about the operator details, go to the Reference section.
Preparations
The following steps repurpose the code to connect to Milvus, quickly set up a collection, and insert over 1,000 randomly generated entities into the collection.
Step 1: Create a collection
Use MilvusClient to connect to the Milvus server and create_collection() to create a collection.
Use MilvusClientV2 to connect to the Milvus server and createCollection() to create a collection.
Use MilvusClient to connect to the Milvus server and createCollection() to create a collection.
from pymilvus import MilvusClient
# 1. Set up a Milvus client
client = MilvusClient(
uri="http://localhost:19530"
)
# 2. Create a collection
client.create_collection(
collection_name="quick_setup",
dimension=5,
)
String CLUSTER_ENDPOINT = "http://localhost:19530";
// 1. Connect to Milvus server
ConnectConfig connectConfig = ConnectConfig.builder()
.uri(CLUSTER_ENDPOINT)
.build();
MilvusClientV2 client = new MilvusClientV2(connectConfig);
// 2. Create a collection in quick setup mode
CreateCollectionReq quickSetupReq = CreateCollectionReq.builder()
.collectionName("quick_setup")
.dimension(5)
.metricType("IP")
.build();
client.createCollection(quickSetupReq);
const { MilvusClient, DataType, sleep } = require("@zilliz/milvus2-sdk-node")
const address = "http://localhost:19530"
// 1. Set up a Milvus Client
client = new MilvusClient({address});
// 2. Create a collection in quick setup mode
await client.createCollection({
collection_name: "quick_setup",
dimension: 5,
});
Step 2: Insert randomly generated entities
Use insert() to insert entities into the collection.
Use insert() to insert entities into the collection.
Use insert() to insert entities into the collection.
# 3. Insert randomly generated vectors
colors = ["green", "blue", "yellow", "red", "black", "white", "purple", "pink", "orange", "brown", "grey"]
data = []
for i in range(1000):
current_color = random.choice(colors)
current_tag = random.randint(1000, 9999)
data.append({
"id": i,
"vector": [ random.uniform(-1, 1) for _ in range(5) ],
"color": current_color,
"tag": current_tag,
"color_tag": f"{current_color}_{str(current_tag)}"
})
print(data[0])
# Output
#
# {
# "id": 0,
# "vector": [
# 0.7371107800002366,
# -0.7290389773227746,
# 0.38367002049157417,
# 0.36996000494220627,
# -0.3641898951462792
# ],
# "color": "yellow",
# "tag": 6781,
# "color_tag": "yellow_6781"
# }
res = client.insert(
collection_name="quick_setup",
data=data
)
print(res)
# Output
#
# {
# "insert_count": 1000,
# "ids": [
# 0,
# 1,
# 2,
# 3,
# 4,
# 5,
# 6,
# 7,
# 8,
# 9,
# "(990 more items hidden)"
# ]
# }
// 3. Insert randomly generated vectors into the collection
List<String> colors = Arrays.asList("green", "blue", "yellow", "red", "black", "white", "purple", "pink", "orange", "brown", "grey");
List<JSONObject> data = new ArrayList<>();
for (int i=0; i<1000; i++) {
Random rand = new Random();
String current_color = colors.get(rand.nextInt(colors.size()-1));
int current_tag = rand.nextInt(8999) + 1000;
JSONObject row = new JSONObject();
row.put("id", Long.valueOf(i));
row.put("vector", Arrays.asList(rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat()));
row.put("color", current_color);
row.put("tag", current_tag);
row.put("color_tag", current_color + '_' + String.valueOf(rand.nextInt(8999) + 1000));
data.add(row);
}
InsertReq insertReq = InsertReq.builder()
.collectionName("quick_setup")
.data(data)
.build();
InsertResp insertResp = client.insert(insertReq);
System.out.println(JSONObject.toJSON(insertResp));
// Output:
// {"insertCnt": 1000}
// 3. Insert randomly generated vectors
const colors = ["green", "blue", "yellow", "red", "black", "white", "purple", "pink", "orange", "brown", "grey"]
var data = []
for (let i = 0; i < 1000; i++) {
current_color = colors[Math.floor(Math.random() * colors.length)]
current_tag = Math.floor(Math.random() * 8999 + 1000)
data.push({
"id": i,
"vector": [Math.random(), Math.random(), Math.random(), Math.random(), Math.random()],
"color": current_color,
"tag": current_tag,
"color_tag": `${current_color}_${current_tag}`
})
}
console.log(data[0])
// Output
//
// {
// id: 0,
// vector: [
// 0.16022394821966035,
// 0.6514875214491056,
// 0.18294484964044666,
// 0.30227694168725394,
// 0.47553087493572255
// ],
// color: 'blue',
// tag: 8907,
// color_tag: 'blue_8907'
// }
//
res = await client.insert({
collection_name: "quick_setup",
data: data
})
console.log(res.insert_cnt)
// Output
//
// 1000
//
Step 3: Create partitions and insert more entities
Use create_partition() to create partitions and insert() to insert more entities into the collection.
Use createPartition() to create partitions and insert() to insert more entities into the collection.
Use createPartition() to create partitions and insert() to insert more entities into the collection.
# 4. Create partitions and insert more entities
client.create_partition(
collection_name="quick_setup",
partition_name="partitionA"
)
client.create_partition(
collection_name="quick_setup",
partition_name="partitionB"
)
data = []
for i in range(1000, 1500):
current_color = random.choice(colors)
data.append({
"id": i,
"vector": [ random.uniform(-1, 1) for _ in range(5) ],
"color": current_color,
"tag": current_tag,
"color_tag": f"{current_color}_{str(current_tag)}"
})
res = client.insert(
collection_name="quick_setup",
data=data,
partition_name="partitionA"
)
print(res)
# Output
#
# {
# "insert_count": 500,
# "ids": [
# 1000,
# 1001,
# 1002,
# 1003,
# 1004,
# 1005,
# 1006,
# 1007,
# 1008,
# 1009,
# "(490 more items hidden)"
# ]
# }
data = []
for i in range(1500, 2000):
current_color = random.choice(colors)
data.append({
"id": i,
"vector": [ random.uniform(-1, 1) for _ in range(5) ],
"color": current_color,
"tag": current_tag,
"color_tag": f"{current_color}_{str(current_tag)}"
})
res = client.insert(
collection_name="quick_setup",
data=data,
partition_name="partitionB"
)
print(res)
# Output
#
# {
# "insert_count": 500,
# "ids": [
# 1500,
# 1501,
# 1502,
# 1503,
# 1504,
# 1505,
# 1506,
# 1507,
# 1508,
# 1509,
# "(490 more items hidden)"
# ]
# }
// 4. Create partitions and insert some more data
CreatePartitionReq createPartitionReq = CreatePartitionReq.builder()
.collectionName("quick_setup")
.partitionName("partitionA")
.build();
client.createPartition(createPartitionReq);
createPartitionReq = CreatePartitionReq.builder()
.collectionName("quick_setup")
.partitionName("partitionB")
.build();
client.createPartition(createPartitionReq);
data.clear();
for (int i=1000; i<1500; i++) {
Random rand = new Random();
String current_color = colors.get(rand.nextInt(colors.size()-1));
int current_tag = rand.nextInt(8999) + 1000;
JSONObject row = new JSONObject();
row.put("id", Long.valueOf(i));
row.put("vector", Arrays.asList(rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat()));
row.put("color", current_color);
row.put("tag", current_tag);
data.add(row);
}
insertReq = InsertReq.builder()
.collectionName("quick_setup")
.data(data)
.partitionName("partitionA")
.build();
insertResp = client.insert(insertReq);
System.out.println(JSONObject.toJSON(insertResp));
// Output:
// {"insertCnt": 500}
data.clear();
for (int i=1500; i<2000; i++) {
Random rand = new Random();
String current_color = colors.get(rand.nextInt(colors.size()-1));
int current_tag = rand.nextInt(8999) + 1000;
JSONObject row = new JSONObject();
row.put("id", Long.valueOf(i));
row.put("vector", Arrays.asList(rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat(), rand.nextFloat()));
row.put("color", current_color);
row.put("tag", current_tag);
data.add(row);
}
insertReq = InsertReq.builder()
.collectionName("quick_setup")
.data(data)
.partitionName("partitionB")
.build();
insertResp = client.insert(insertReq);
System.out.println(JSONObject.toJSON(insertResp));
// Output:
// {"insertCnt": 500}
// 4. Create partitions and insert more entities
await client.createPartition({
collection_name: "quick_setup",
partition_name: "partitionA"
})
await client.createPartition({
collection_name: "quick_setup",
partition_name: "partitionB"
})
data = []
for (let i = 1000; i < 1500; i++) {
current_color = colors[Math.floor(Math.random() * colors.length)]
current_tag = Math.floor(Math.random() * 8999 + 1000)
data.push({
"id": i,
"vector": [Math.random(), Math.random(), Math.random(), Math.random(), Math.random()],
"color": current_color,
"tag": current_tag,
"color_tag": `${current_color}_${current_tag}`
})
}
res = await client.insert({
collection_name: "quick_setup",
data: data,
partition_name: "partitionA"
})
console.log(res.insert_cnt)
// Output
//
// 500
//
await sleep(5000)
data = []
for (let i = 1500; i < 2000; i++) {
current_color = colors[Math.floor(Math.random() * colors.length)]
current_tag = Math.floor(Math.random() * 8999 + 1000)
data.push({
"id": i,
"vector": [Math.random(), Math.random(), Math.random(), Math.random(), Math.random()],
"color": current_color,
"tag": current_tag,
"color_tag": `${current_color}_${current_tag}`
})
}
res = await client.insert({
collection_name: "quick_setup",
data: data,
partition_name: "partitionB"
})
console.log(res.insert_cnt)
// Output
//
// 500
//
Get Entities by ID
If you know the IDs of the entities of your interests, you can use the get() method.
If you know the IDs of the entities of your interests, you can use the get() method.
If you know the IDs of the entities of your interests, you can use the get() method.
# 4. Get entities by ID
res = client.get(
collection_name="quick_setup",
ids=[0, 1, 2]
)
print(res)
# Output
#
# [
# {
# "id": 0,
# "vector": [
# 0.68824464,
# 0.6552274,
# 0.33593303,
# -0.7099536,
# -0.07070546
# ],
# "color_tag": "green_2006",
# "color": "green"
# },
# {
# "id": 1,
# "vector": [
# -0.98531723,
# 0.33456197,
# 0.2844234,
# 0.42886782,
# 0.32753858
# ],
# "color_tag": "white_9298",
# "color": "white"
# },
# {
# "id": 2,
# "vector": [
# -0.9886812,
# -0.44129863,
# -0.29859528,
# 0.06059075,
# -0.43817034
# ],
# "color_tag": "grey_5312",
# "color": "grey"
# }
# ]
// 5. Get entities by ID
GetReq getReq = GetReq.builder()
.collectionName("quick_setup")
.ids(Arrays.asList(0L, 1L, 2L))
.build();
GetResp entities = client.get(getReq);
System.out.println(JSONObject.toJSON(entities));
// Output:
// {"getResults": [
// {"entity": {
// "color": "white",
// "color_tag": "white_4597",
// "vector": [
// 0.09665024,
// 0.1163497,
// 0.0701347,
// 0.32577968,
// 0.40943468
// ],
// "tag": 8946,
// "id": 0
// }},
// {"entity": {
// "color": "green",
// "color_tag": "green_3039",
// "vector": [
// 0.90689456,
// 0.4377399,
// 0.75387514,
// 0.36454988,
// 0.8702918
// ],
// "tag": 2341,
// "id": 1
// }},
// {"entity": {
// "color": "white",
// "color_tag": "white_8708",
// "vector": [
// 0.9757728,
// 0.13974023,
// 0.8023141,
// 0.61947155,
// 0.8290197
// ],
// "tag": 9913,
// "id": 2
// }}
// ]}
// 5. Get entities by id
res = await client.get({
collection_name: "quick_setup",
ids: [0, 1, 2],
output_fields: ["vector", "color_tag"]
})
console.log(res.data)
// Output
//
// [
// {
// vector: [
// 0.16022394597530365,
// 0.6514875292778015,
// 0.18294484913349152,
// 0.30227693915367126,
// 0.47553086280822754
// ],
// '$meta': { color: 'blue', tag: 8907, color_tag: 'blue_8907' },
// id: '0'
// },
// {
// vector: [
// 0.2459285855293274,
// 0.4974019527435303,
// 0.2154673933982849,
// 0.03719571232795715,
// 0.8348019123077393
// ],
// '$meta': { color: 'grey', tag: 3710, color_tag: 'grey_3710' },
// id: '1'
// },
// {
// vector: [
// 0.9404329061508179,
// 0.49662265181541443,
// 0.8088793158531189,
// 0.9337621331214905,
// 0.8269071578979492
// ],
// '$meta': { color: 'blue', tag: 2993, color_tag: 'blue_2993' },
// id: '2'
// }
// ]
//
Get entities from partitions
You can also get entities from specific partitions.
# 5. Get entities from partitions
res = client.get(
collection_name="quick_setup",
ids=[1000, 1001, 1002],
partition_names=["partitionA"]
)
print(res)
# Output
#
# [
# {
# "color": "green",
# "tag": 1995,
# "color_tag": "green_1995",
# "id": 1000,
# "vector": [
# 0.7807706,
# 0.8083741,
# 0.17276904,
# -0.8580777,
# 0.024156934
# ]
# },
# {
# "color": "red",
# "tag": 1995,
# "color_tag": "red_1995",
# "id": 1001,
# "vector": [
# 0.065074645,
# -0.44882354,
# -0.29479212,
# -0.19798489,
# -0.77542555
# ]
# },
# {
# "color": "green",
# "tag": 1995,
# "color_tag": "green_1995",
# "id": 1002,
# "vector": [
# 0.027934508,
# -0.44199976,
# -0.40262738,
# -0.041511405,
# 0.024782438
# ]
# }
# ]
// 5. Get entities by ID in a partition
getReq = GetReq.builder()
.collectionName("quick_setup")
.ids(Arrays.asList(1001L, 1002L, 1003L))
.partitionName("partitionA")
.build();
entities = client.get(getReq);
System.out.println(JSONObject.toJSON(entities));
// Output:
// {"getResults": [
// {"entity": {
// "color": "yellow",
// "vector": [
// 0.4300114,
// 0.599917,
// 0.799163,
// 0.75395125,
// 0.89947814
// ],
// "id": 1001,
// "tag": 5803
// }},
// {"entity": {
// "color": "blue",
// "vector": [
// 0.009218454,
// 0.64637834,
// 0.19815737,
// 0.30519038,
// 0.8218663
// ],
// "id": 1002,
// "tag": 7212
// }},
// {"entity": {
// "color": "black",
// "vector": [
// 0.76521933,
// 0.7818409,
// 0.16976339,
// 0.8719652,
// 0.1434964
// ],
// "id": 1003,
// "tag": 1710
// }}
// ]}
// 5.1 Get entities by id in a partition
res = await client.get({
collection_name: "quick_setup",
ids: [1000, 1001, 1002],
partition_names: ["partitionA"],
output_fields: ["vector", "color_tag"]
})
console.log(res.data)
// Output
//
// [
// {
// id: '1000',
// vector: [
// 0.014254206791520119,
// 0.5817716121673584,
// 0.19793470203876495,
// 0.8064294457435608,
// 0.7745839357376099
// ],
// '$meta': { color: 'white', tag: 5996, color_tag: 'white_5996' }
// },
// {
// id: '1001',
// vector: [
// 0.6073881983757019,
// 0.05214758217334747,
// 0.730999231338501,
// 0.20900958776474,
// 0.03665429726243019
// ],
// '$meta': { color: 'grey', tag: 2834, color_tag: 'grey_2834' }
// },
// {
// id: '1002',
// vector: [
// 0.48877206444740295,
// 0.34028753638267517,
// 0.6527213454246521,
// 0.9763909578323364,
// 0.8031482100486755
// ],
// '$meta': { color: 'pink', tag: 9107, color_tag: 'pink_9107' }
// }
// ]
//
Use Basic Operators
In this section, you will find examples of how to use basic operators in scalar filtering. You can apply these filters to vector searches and data deletions too.
For more information, refer to query() in the SDK reference.
For more information, refer to query() in the SDK reference.
For more information, refer to query() in the SDK reference.
Filter entities with their tag values falling between 1,000 to 1,500.
# 6. Use basic operators res = client.query( collection_name="quick_setup", filter="1000 < tag < 1500", output_fields=["color_tag"], limit=3 ) print(res) # Output # # [ # { # "id": 1, # "color_tag": "pink_1023" # }, # { # "id": 41, # "color_tag": "red_1483" # }, # { # "id": 44, # "color_tag": "grey_1146" # } # ]// 6. Use basic operators QueryReq queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("1000 < tag < 1500") .outputFields(Arrays.asList("color_tag")) .limit(3) .build(); QueryResp queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [ // {"entity": { // "color_tag": "white_7588", // "id": 34 // }}, // {"entity": { // "color_tag": "orange_4989", // "id": 64 // }}, // {"entity": { // "color_tag": "white_3415", // "id": 73 // }} // ]}// 6. Use basic operators res = await client.query({ collection_name: "quick_setup", filter: "1000 < tag < 1500", output_fields: ["color_tag"], limit: 3 }) console.log(res.data) // Output // // [ // { // '$meta': { color: 'pink', tag: 1050, color_tag: 'pink_1050' }, // id: '6' // }, // { // '$meta': { color: 'purple', tag: 1174, color_tag: 'purple_1174' }, // id: '24' // }, // { // '$meta': { color: 'orange', tag: 1023, color_tag: 'orange_1023' }, // id: '40' // } // ] //Filter entities with their color values set to brown.
res = client.query( collection_name="quick_setup", filter='color == "brown"', output_fields=["color_tag"], limit=3 ) print(res) # Output # # [ # { # "color_tag": "brown_5343", # "id": 15 # }, # { # "color_tag": "brown_3167", # "id": 27 # }, # { # "color_tag": "brown_3100", # "id": 30 # } # ]queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("color == \"brown\"") .outputFields(Arrays.asList("color_tag")) .limit(3) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [ // {"entity": { // "color_tag": "brown_7792", // "id": 3 // }}, // {"entity": { // "color_tag": "brown_9695", // "id": 7 // }}, // {"entity": { // "color_tag": "brown_2551", // "id": 15 // }} // ]}res = await client.query({ collection_name: "quick_setup", filter: 'color == "brown"', output_fields: ["color_tag"], limit: 3 }) console.log(res.data) // Output // // [ // { // '$meta': { color: 'brown', tag: 6839, color_tag: 'brown_6839' }, // id: '22' // }, // { // '$meta': { color: 'brown', tag: 7849, color_tag: 'brown_7849' }, // id: '32' // }, // { // '$meta': { color: 'brown', tag: 7855, color_tag: 'brown_7855' }, // id: '33' // } // ] //Filter entities with their color values not set to green and purple.
res = client.query( collection_name="quick_setup", filter='color not in ["green", "purple"]', output_fields=["color_tag"], limit=3 ) print(res) # Output # # [ # { # "color_tag": "yellow_6781", # "id": 0 # }, # { # "color_tag": "pink_1023", # "id": 1 # }, # { # "color_tag": "blue_3972", # "id": 2 # } # ]queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("color not in [\"green\", \"purple\"]") .outputFields(Arrays.asList("color_tag")) .limit(3) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [ // {"entity": { // "color_tag": "white_4597", // "id": 0 // }}, // {"entity": { // "color_tag": "white_8708", // "id": 2 // }}, // {"entity": { // "color_tag": "brown_7792", // "id": 3 // }} // ]}res = await client.query({ collection_name: "quick_setup", filter: 'color not in ["green", "purple"]', output_fields: ["color_tag"], limit: 3 }) console.log(res.data) // Output // // [ // { // '$meta': { color: 'blue', tag: 8907, color_tag: 'blue_8907' }, // id: '0' // }, // { // '$meta': { color: 'grey', tag: 3710, color_tag: 'grey_3710' }, // id: '1' // }, // { // '$meta': { color: 'blue', tag: 2993, color_tag: 'blue_2993' }, // id: '2' // } // ] //Filter articles whose color tags start with red.
res = client.query( collection_name="quick_setup", filter='color_tag like "red%"', output_fields=["color_tag"], limit=3 ) print(res) # Output # # [ # { # "color_tag": "red_6443", # "id": 17 # }, # { # "color_tag": "red_1483", # "id": 41 # }, # { # "color_tag": "red_4348", # "id": 47 # } # ]queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("color_tag like \"red%\"") .outputFields(Arrays.asList("color_tag")) .limit(3) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [ // {"entity": { // "color_tag": "red_4929", // "id": 9 // }}, // {"entity": { // "color_tag": "red_8284", // "id": 13 // }}, // {"entity": { // "color_tag": "red_3021", // "id": 44 // }} // ]}res = await client.query({ collection_name: "quick_setup", filter: 'color_tag like "red%"', output_fields: ["color_tag"], limit: 3 }) console.log(res.data) // Output // // [ // { // '$meta': { color: 'red', tag: 8773, color_tag: 'red_8773' }, // id: '17' // }, // { // '$meta': { color: 'red', tag: 9197, color_tag: 'red_9197' }, // id: '34' // }, // { // '$meta': { color: 'red', tag: 7914, color_tag: 'red_7914' }, // id: '46' // } // ] //Filter entities with their colors set to red and tag values within the range from 1,000 to 1,500.
res = client.query( collection_name="quick_setup", filter='(color == "red") and (1000 < tag < 1500)', output_fields=["color_tag"], limit=3 ) print(res) # Output # # [ # { # "color_tag": "red_1483", # "id": 41 # }, # { # "color_tag": "red_1100", # "id": 94 # }, # { # "color_tag": "red_1343", # "id": 526 # } # ]queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("(color == \"red\") and (1000 < tag < 1500)") .outputFields(Arrays.asList("color_tag")) .limit(3) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [ // {"entity": { // "color_tag": "red_8124", // "id": 83 // }}, // {"entity": { // "color_tag": "red_5358", // "id": 501 // }}, // {"entity": { // "color_tag": "red_3564", // "id": 638 // }} // ]}res = await client.query({ collection_name: "quick_setup", filter: '(color == "red") and (1000 < tag < 1500)', output_fields: ["color_tag"], limit: 3 }) console.log(res.data) // Output // // [ // { // '$meta': { color: 'red', tag: 1436, color_tag: 'red_1436' }, // id: '67' // }, // { // '$meta': { color: 'red', tag: 1463, color_tag: 'red_1463' }, // id: '160' // }, // { // '$meta': { color: 'red', tag: 1073, color_tag: 'red_1073' }, // id: '291' // } // ] //
Use Advanced Operators
In this section, you will find examples of how to use advanced operators in scalar filtering. You can apply these filters to vector searches and data deletions too.
Count entities
Counts the total number of entities in a collection.
# 7. Use advanced operators # Count the total number of entities in a collection res = client.query( collection_name="quick_setup", output_fields=["count(*)"] ) print(res) # Output # # [ # { # "count(*)": 2000 # } # ]// 7. Use advanced operators // Count the total number of entities in the collection queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("") .outputFields(Arrays.asList("count(*)")) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [{"entity": {"count(*)": 2000}}]}// 7. Use advanced operators // Count the total number of entities in a collection res = await client.query({ collection_name: "quick_setup", output_fields: ["count(*)"] }) console.log(res.data) // Output // // [ { 'count(*)': '2000' } ] //Counts the total number of entities in specific partitions.
# Count the number of entities in a partition res = client.query( collection_name="quick_setup", output_fields=["count(*)"], partition_names=["partitionA"] ) print(res) # Output # # [ # { # "count(*)": 500 # } # ]// Count the number of entities in a partition queryReq = QueryReq.builder() .collectionName("quick_setup") .partitionNames(Arrays.asList("partitionA")) .filter("") .outputFields(Arrays.asList("count(*)")) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [{"entity": {"count(*)": 500}}]}// Count the number of entities in a partition res = await client.query({ collection_name: "quick_setup", output_fields: ["count(*)"], partition_names: ["partitionA"] }) console.log(res.data) // Output // // [ { 'count(*)': '500' } ] //Counts the number of entities that match a filtering condition
# Count the number of entities that match a specific filter res = client.query( collection_name="quick_setup", filter='(color == "red") and (1000 < tag < 1500)', output_fields=["count(*)"], ) print(res) # Output # # [ # { # "count(*)": 3 # } # ]// Count the number of entities that match a specific filter queryReq = QueryReq.builder() .collectionName("quick_setup") .filter("(color == \"red\") and (1000 < tag < 1500)") .outputFields(Arrays.asList("count(*)")) .build(); queryResp = client.query(queryReq); System.out.println(JSONObject.toJSON(queryResp)); // Output: // {"queryResults": [{"entity": {"count(*)": 7}}]}// Count the number of entities that match a specific filter res = await client.query({ collection_name: "quick_setup", filter: '(color == "red") and (1000 < tag < 1500)', output_fields: ["count(*)"] }) console.log(res.data) // Output // // [ { 'count(*)': '10' } ] //
Reference on scalar filters
Basic Operators
A boolean expression is always a string comprising field names joined by operators. In this section, you will learn more about basic operators.
| Operator | Description |
|---|---|
| and (&&) | True if both operands are true |
| or (||) | True if either operand is true |
| +, -, *, / | Addition, subtraction, multiplication, and division |
| ** | Exponent |
| % | Modulus |
| <, > | Less than, greater than |
| ==, != | Equal to, not equal to |
| <=, >= | Less than or equal to, greater than or equal to |
| not | Reverses the result of a given condition. |
| like | Compares a value to similar values using wildcard operators. For example, like "prefix%" matches strings that begin with "prefix". |
| in | Tests if an expression matches any value in a list of values. |
Advanced operators
count(*)Counts the exact number of entities in the collection. Use this as an output field to get the exact number of entities in a collection or partition.
notes
This applies to loaded collections. You should use it as the only output field.