Nosql-neo4j-Cypher 语句 概要
2022-09-15 本文已影响0人
Viterbi
目录: [TOC]
概要
读子句Reading clauses
Clause | Description |
---|---|
MATCH | Specify the patterns to search for in the database. |
OPTIONAL MATCH | Specify the patterns to search for in the database while using nulls for missing parts of the pattern. |
投影子句Projecting clauses
Clause | Description |
---|---|
RETURN … [AS] | Defines what to include in the query result set. |
WITH … [AS] | Allows query parts to be chained together, piping the results from one to be used as starting points or criteria in the next. |
UNWIND … [AS] | Expands a list into a sequence of rows. |
读子句Reading sub-clauses
Sub-clause | Description |
---|---|
WHERE | Adds constraints to the patterns in a MATCH or OPTIONAL MATCH clause or filters the results of a WITH clause. |
WHERE EXISTS {…} | An existential sub-query used to filter the results of a MATCH, OPTIONAL MATCH or WITH clause. |
ORDER BY [ASC[ENDING] DESC[ENDING]] | A sub-clause following RETURN or WITH, specifying that the output should be sorted in either ascending (the default) or descending order. |
SKIP | Defines from which row to start including the rows in the output. |
LIMIT | Constrains the number of rows in the output. |
读暗示Reading hints
Hint | Description |
---|---|
USING INDEX | Index hints are used to specify which index, if any, the planner should use as a starting point. |
USING INDEX SEEK | Index seek hint instructs the planner to use an index seek for this clause. |
USING SCAN | Scan hints are used to force the planner to do a label scan (followed by a filtering operation) instead of using an index. |
USING JOIN | Join hints are used to enforce a join operation at specified points. |
写子句Writing clauses
Clause | Description |
---|---|
CREATE | Create nodes and relationships. |
DELETE | Delete nodes, relationships or paths. Any node to be deleted must also have all associated relationships explicitly deleted. |
DETACH DELETE | Delete a node or set of nodes. All associated relationships will automatically be deleted. |
SET | Update labels on nodes and properties on nodes and relationships. |
REMOVE | Remove properties and labels from nodes and relationships. |
FOREACH | Update data within a list, whether components of a path, or the result of aggregation. |
读写子句Reading/Writing clauses
Clause | Description |
---|---|
MERGE | Ensures that a pattern exists in the graph. Either the pattern already exists, or it needs to be created. |
— ON CREATE | Used in conjunction with MERGE, this write sub-clause specifies the actions to take if the pattern needs to be created. |
— ON MATCH | Used in conjunction with MERGE, this write sub-clause specifies the actions to take if the pattern already exists. |
CALL […YIELD] | Invokes a procedure deployed in the database and return any results. |
集合操作
子查询语句
多个graph
导入数据
管理员语句
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