Method: Google::Cloud::Spanner::Client#execute_query

Defined in:
lib/google/cloud/spanner/client.rb

#execute_query(sql, params: nil, types: nil, single_use: nil, query_options: nil, request_options: nil, call_options: nil, directed_read_options: nil) ⇒ Google::Cloud::Spanner::Results Also known as: execute, query, execute_sql

Executes a SQL query.

The following settings can be provided:

  • :exclude_replicas (Hash) Exclude_replicas indicates what replicas should be excluded from serving requests. Spanner will not route requests to the replicas in this list.
  • :include_replicas (Hash) Include_replicas indicates the order of replicas to process the request. If auto_failover_disabled is set to true and all replicas are exhausted without finding a healthy replica, Spanner will wait for a replica in the list to become available, requests may fail due to DEADLINE_EXCEEDED errors.

Examples:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

results = db.execute_query "SELECT * FROM users"

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Query using query parameters:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

results = db.execute_query(
  "SELECT * FROM users WHERE active = @active",
  params: { active: true }
)

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Query with a SQL STRUCT query parameter as a Hash:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

user_hash = { id: 1, name: "Charlie", active: false }

results = db.execute_query(
  "SELECT * FROM users WHERE " \
  "ID = @user_struct.id " \
  "AND name = @user_struct.name " \
  "AND active = @user_struct.active",
  params: { user_struct: user_hash }
)

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Specify the SQL STRUCT type using Fields object:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

user_type = db.fields id: :INT64, name: :STRING, active: :BOOL
user_hash = { id: 1, name: nil, active: false }

results = db.execute_query(
  "SELECT * FROM users WHERE " \
  "ID = @user_struct.id " \
  "AND name = @user_struct.name " \
  "AND active = @user_struct.active",
  params: { user_struct: user_hash },
  types: { user_struct: user_type }
)

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Or, query with a SQL STRUCT as a typed Data object:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

user_type = db.fields id: :INT64, name: :STRING, active: :BOOL
user_data = user_type.struct id: 1, name: nil, active: false

results = db.execute_query(
  "SELECT * FROM users WHERE " \
  "ID = @user_struct.id " \
  "AND name = @user_struct.name " \
  "AND active = @user_struct.active",
  params: { user_struct: user_data }
)

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Query using query options:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

results = db.execute_query \
  "SELECT * FROM users", query_options: {
    optimizer_version: "1",
    optimizer_statistics_package: "auto_20191128_14_47_22UTC"
  }

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Query using custom timeout and retry policy:

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

timeout = 30.0
retry_policy = {
  initial_delay: 0.25,
  max_delay:     32.0,
  multiplier:    1.3,
  retry_codes:   ["UNAVAILABLE"]
}
call_options = { timeout: timeout, retry_policy: retry_policy }

results = db.execute_query \
  "SELECT * FROM users", call_options: call_options

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Using request options.

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

request_options = { priority: :PRIORITY_MEDIUM }
results = db.execute_query "SELECT * FROM users",
                           request_options: request_options

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Query using tag for request query statistics collection.

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new

db = spanner.client "my-instance", "my-database"

request_options = { tag: "Read-Users" }
results = db.execute_query "SELECT * FROM users",
                           request_options: request_options

results.rows.each do |row|
  puts "User #{row[:id]} is #{row[:name]}"
end

Parameters:

  • sql (String)

    The SQL query string. See Query syntax.

    The SQL query string can contain parameter placeholders. A parameter placeholder consists of "@" followed by the parameter name. Parameter names consist of any combination of letters, numbers, and underscores.

  • params (Hash) (defaults to: nil)

    SQL parameters for the query string. The parameter placeholders, minus the "@", are the the hash keys, and the literal values are the hash values. If the query string contains something like "WHERE id > @msg_id", then the params must contain something like :msg_id => 1.

    Ruby types are mapped to Spanner types as follows:

    Spanner Ruby Notes
    BOOL true/false
    INT64 Integer
    FLOAT64 Float
    NUMERIC BigDecimal
    STRING String
    DATE Date
    TIMESTAMP Time, DateTime
    BYTES File, IO, StringIO, or similar
    ARRAY Array Nested arrays are not supported.
    STRUCT Hash, Data

    See Data types.

    See Data Types - Constructing a STRUCT.

  • types (Hash) (defaults to: nil)

    Types of the SQL parameters in params. It is not always possible for Cloud Spanner to infer the right SQL type from a value in params. In these cases, the types hash must be used to specify the SQL type for these values.

    The keys of the hash should be query string parameter placeholders, minus the "@". The values of the hash should be Cloud Spanner type codes from the following list:

    • :BOOL
    • :BYTES
    • :DATE
    • :FLOAT64
    • :NUMERIC
    • :INT64
    • :STRING
    • :TIMESTAMP
    • Array - Lists are specified by providing the type code in an array. For example, an array of integers are specified as [:INT64].
    • Fields - Types for STRUCT values (Hash/Data objects) are specified using a Fields object.

    Types are optional.

  • single_use (Hash) (defaults to: nil)

    Perform the read with a single-use snapshot (read-only transaction). (See TransactionOptions.) If no value is specified for this parameter, Cloud Spanner will use a single use read-only transaction with strong timestamp bound as default. The snapshot can be created by providing exactly one of the following options in the hash:

    • Strong
      • :strong (true, false) Read at a timestamp where all previously committed transactions are visible.
    • Exact

      • :timestamp/:read_timestamp (Time, DateTime) Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read will block until the specified timestamp, modulo the read's deadline.

      Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data.

      • :staleness/:exact_staleness (Numeric) Executes all reads at a timestamp that is exactly the number of seconds provided old. The timestamp is chosen soon after the read is started.

      Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps.

      Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of single-use bounded_staleness.

    • Bounded

      • :bounded_timestamp/:min_read_timestamp (Time, DateTime) Executes all reads at a timestamp greater than the value provided.

      This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known.

      • :bounded_staleness/:max_staleness (Numeric) Read data at a timestamp greater than or equal to the number of seconds provided. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client's local clock is substantially skewed from Cloud Spanner commit timestamps.

      Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind.

  • query_options (Hash) (defaults to: nil)

    A hash of values to specify the custom query options for executing SQL query. Query options are optional. The following settings can be provided:

    • :optimizer_version (String) The version of optimizer to use. Empty to use database default. "latest" to use the latest available optimizer version.
    • :optimizer_statistics_package (String) Statistics package to use. Empty to use the database default.
  • request_options (Hash) (defaults to: nil)

    Common request options.

    • :priority (Symbol) The relative priority for requests. The priority acts as a hint to the Cloud Spanner scheduler and does not guarantee priority or order of execution. Valid values are :PRIORITY_LOW, :PRIORITY_MEDIUM, :PRIORITY_HIGH. If priority not set then default is PRIORITY_UNSPECIFIED is equivalent to :PRIORITY_HIGH.
    • :tag (String) A per-request tag which can be applied to queries or reads, used for statistics collection. Tag must be a valid identifier of the form: [a-zA-Z][a-zA-Z0-9_\-] between 2 and 64 characters in length.
  • call_options (Hash) (defaults to: nil)

    A hash of values to specify the custom call options, e.g., timeout, retries, etc. Call options are optional. The following settings can be provided:

    • :timeout (Numeric) A numeric value of custom timeout in seconds that overrides the default setting.
    • :retry_policy (Hash) A hash of values that overrides the default setting of retry policy with the following keys:
      • :initial_delay (Numeric) - The initial delay in seconds.
      • :max_delay (Numeric) - The max delay in seconds.
      • :multiplier (Numeric) - The incremental backoff multiplier.
      • :retry_codes (Array<String>) - The error codes that should trigger a retry.
  • directed_read_options (Hash) (defaults to: nil)

    Client options used to set the directed_read_options for all ReadRequests and ExecuteSqlRequests that indicates which replicas or regions should be used for non-transactional reads or queries. Will represent Google::Cloud::Spanner::V1::DirectedReadOptions

Returns:



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# File 'lib/google/cloud/spanner/client.rb', line 460

def execute_query sql, params: nil, types: nil, single_use: nil,
                  query_options: nil, request_options: nil,
                  call_options: nil, directed_read_options: nil
  validate_single_use_args! single_use
  ensure_service!

  params, types = Convert.to_input_params_and_types params, types
  request_options = Convert.to_request_options request_options,
                                               tag_type: :request_tag
  single_use_tx = single_use_transaction single_use
  route_to_leader = LARHeaders.execute_query true
  results = nil
  @pool.with_session do |session|
    results = session.execute_query \
      sql, params: params, types: types, transaction: single_use_tx,
      query_options: query_options, request_options: request_options,
      call_options: call_options, directed_read_options: (directed_read_options || @directed_read_options),
      route_to_leader: route_to_leader
  end
  results
end